diff --git a/DESCRIPTION b/DESCRIPTION
index ad30e22..36548b1 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -45,6 +45,7 @@ Suggests:
     BSgenome.Drerio.UCSC.danRer7,
     DESeq2,
     FANTOM3and4CAGE,
+    ggseqlogo,
     BiocStyle,
     knitr,
     rmarkdown
@@ -84,6 +85,7 @@ Collate:
     'ShiftingFunctions.R'
     'ShiftingMethods.R'
     'StrandInvaders.R'
+    'TSSlogo.R'
 LazyData: true
 VignetteBuilder: knitr
 RoxygenNote: 7.2.1
diff --git a/NAMESPACE b/NAMESPACE
index a9aed44..3784ebf 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -27,6 +27,7 @@ export(CTSStoGenes)
 export(CustomConsensusClusters)
 export(GeneExpDESeq2)
 export(GeneExpSE)
+export(TSSlogo)
 export(aggregateTagClusters)
 export(annotateCTSS)
 export(annotateConsensusClusters)
@@ -89,6 +90,7 @@ importFrom(BiocParallel,MulticoreParam)
 importFrom(BiocParallel,SerialParam)
 importFrom(BiocParallel,bplapply)
 importFrom(BiocParallel,multicoreWorkers)
+importFrom(Biostrings,consensusMatrix)
 importFrom(CAGEfightR,quickEnhancers)
 importFrom(GenomeInfoDb,"genome<-")
 importFrom(GenomeInfoDb,"seqlevels<-")
diff --git a/R/TSSlogo.R b/R/TSSlogo.R
new file mode 100644
index 0000000..6a4cb59
--- /dev/null
+++ b/R/TSSlogo.R
@@ -0,0 +1,87 @@
+#' TSS logo
+#' 
+#' Plot the sequence logo of the region flanking the TSS.  When this function
+#' is given _tag clusters_ or _consensus clusters_, it uses the _dominant peak_
+#' as the transcription start site.
+#' 
+#' This function will only work if the [`CAGEexp`] object was built with a
+#' [`BSgenome`] package, as it needs to extract genomic sequences.
+#' 
+#' @param x A [`CTSS`], a [`TagClusters`] or a [`ConsensusClusters`] object.
+#' @param upstream Number of bases to plot upstream the TSS.
+#' @param downstream Number of bases to plot downstream the TSS, including the
+#'        TSS itself.
+#' 
+#' @returns A [`ggplot2::ggplot`] object showing the sequence logo.  The
+#' coordinates displayed are negative for upstream sequences and positive
+#' downstream.  The position of the TSS is set to 1.
+#' 
+#' @family CAGEr plot functions
+#' @family CAGEr TSS functions
+#' 
+#' @author Charles Plessy
+#' 
+#' @examples
+#' TSSlogo(exampleCAGEexp|>consensusClustersGR(), 20, 10)
+#' 
+#' @importFrom Biostrings consensusMatrix
+#' 
+#' @export
+
+setGeneric("TSSlogo",
+           function (x, upstream = 10, downstream = 10)
+             standardGeneric("TSSlogo"))
+
+#' @rdname TSSlogo
+
+setMethod("TSSlogo", signature("CAGEexp"),
+          function (x, upstream = 10, downstream = 10) {
+  TSSlogo(CTSScoordinatesGR(object), upstream = upstream, downstream = downstream)
+})
+
+#' @rdname TSSlogo
+
+setMethod("TSSlogo", signature("TagClusters"),
+          function (x, upstream = 10, downstream = 10) {
+  TSSlogo(object$dominant_ctss |> as("CTSS"), upstream = upstream, downstream = downstream)
+})
+
+setMethod("TSSlogo", signature("ConsensusClusters"),
+          function (x, upstream = 10, downstream = 10) {
+  TSSlogo(object$dominant_ctss |> as("CTSS"), upstream = upstream, downstream = downstream)
+})
+
+#' @rdname TSSlogo
+
+setMethod("TSSlogo", signature("CTSS"),
+          function (x, upstream = 10, downstream = 10) {
+  .TSSlogo(object, upstream = upstream, downstream = downstream)
+})
+
+.TSSlogo <- function(x, upstream=10, downstream=10) {
+  if (! requireNamespace("ggseqlogo"))
+    stop("This function requires the ", dQuote("ggseqlogo"), " package; please install it.")
+  # Extract sequences
+  upstreamRanges <-
+    promoters(x = x, upstream = upstream, downstream = downstream) |>
+    suppressWarnings() # This warns about off-genome coordinates, but we will fix this below.
+  
+  # Discard ranges that would be trimmed 
+  upstreamRanges_trimmed <- upstreamRanges |> trim()
+  upstreamRanges <- upstreamRanges[width(upstreamRanges) == width(upstreamRanges_trimmed)]
+  
+  # Extract sequences
+  bsgenome <- getBSgenome(unique(genome(x)))
+  upstreamSeq <- getSeq(bsgenome, upstreamRanges)
+  
+  # Plot sequence logo
+  letter_counts <- consensusMatrix(upstreamSeq)
+  probs <- prop.table(letter_counts[1:4,], 2)
+  gg <- ggseqlogo::ggseqlogo(probs)
+  # Circumvent "Scale for x is already present." warning.
+  gg$scales$scales[[2]]$breaks <- seq(    1       , upstream + downstream, by = 1)
+  gg$scales$scales[[2]]$labels <- seq(1 - upstream,            downstream, by = 1)
+  gg$scales$scales[[1]]$breaks <- seq(    1       , upstream + downstream, by = 1)
+  gg$scales$scales[[1]]$labels <- seq(1 - upstream,            downstream, by = 1)
+  gg
+}
\ No newline at end of file
diff --git a/man/TSSlogo.Rd b/man/TSSlogo.Rd
new file mode 100644
index 0000000..5cd4b47
--- /dev/null
+++ b/man/TSSlogo.Rd
@@ -0,0 +1,57 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/TSSlogo.R
+\name{TSSlogo}
+\alias{TSSlogo}
+\alias{TSSlogo,CAGEexp-method}
+\alias{TSSlogo,TagClusters-method}
+\alias{TSSlogo,CTSS-method}
+\title{TSS logo}
+\usage{
+TSSlogo(x, upstream = 10, downstream = 10)
+
+\S4method{TSSlogo}{CAGEexp}(x, upstream = 10, downstream = 10)
+
+\S4method{TSSlogo}{TagClusters}(x, upstream = 10, downstream = 10)
+
+\S4method{TSSlogo}{CTSS}(x, upstream = 10, downstream = 10)
+}
+\arguments{
+\item{x}{A \code{\link{CTSS}}, a \code{\link{TagClusters}} or a \code{\link{ConsensusClusters}} object.}
+
+\item{upstream}{Number of bases to plot upstream the TSS.}
+
+\item{downstream}{Number of bases to plot downstream the TSS, including the
+TSS itself.}
+}
+\value{
+A \code{\link[ggplot2:ggplot]{ggplot2::ggplot}} object showing the sequence logo.  The
+coordinates displayed are negative for upstream sequences and positive
+downstream.  The position of the TSS is set to 1.
+}
+\description{
+Plot the sequence logo of the region flanking the TSS.  When this function
+is given \emph{tag clusters} or \emph{consensus clusters}, it uses the \emph{dominant peak}
+as the transcription start site.
+}
+\details{
+This function will only work if the \code{\link{CAGEexp}} object was built with a
+\code{\link{BSgenome}} package, as it needs to extract genomic sequences.
+}
+\examples{
+TSSlogo(exampleCAGEexp|>consensusClustersGR(), 20, 10)
+
+}
+\seealso{
+Other CAGEr plot functions: 
+\code{\link{hanabiPlot}()},
+\code{\link{plotAnnot}()},
+\code{\link{plotCorrelation}()},
+\code{\link{plotExpressionProfiles}()},
+\code{\link{plotInterquantileWidth}()},
+\code{\link{plotReverseCumulatives}()}
+}
+\author{
+Charles Plessy
+}
+\concept{CAGEr TSS functions}
+\concept{CAGEr plot functions}
diff --git a/man/hanabiPlot.Rd b/man/hanabiPlot.Rd
index 423829b..8f45459 100644
--- a/man/hanabiPlot.Rd
+++ b/man/hanabiPlot.Rd
@@ -52,6 +52,7 @@ Other CAGEr richness functions:
 \code{\link{plot.hanabi}()}
 
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{plotAnnot}()},
 \code{\link{plotCorrelation}()},
 \code{\link{plotExpressionProfiles}()},
diff --git a/man/plotAnnot.Rd b/man/plotAnnot.Rd
index ad1f95f..eac30af 100644
--- a/man/plotAnnot.Rd
+++ b/man/plotAnnot.Rd
@@ -72,6 +72,7 @@ Other CAGEr annotation functions:
 \code{\link{ranges2names}()}
 
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{hanabiPlot}()},
 \code{\link{plotCorrelation}()},
 \code{\link{plotExpressionProfiles}()},
diff --git a/man/plotCorrelation.Rd b/man/plotCorrelation.Rd
index 6f7c832..c728d8f 100644
--- a/man/plotCorrelation.Rd
+++ b/man/plotCorrelation.Rd
@@ -179,6 +179,7 @@ plotCorrelation2(exampleCAGEexp, what = "consensusClusters", value = "normalized
 }
 \seealso{
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{hanabiPlot}()},
 \code{\link{plotAnnot}()},
 \code{\link{plotExpressionProfiles}()},
diff --git a/man/plotExpressionProfiles.Rd b/man/plotExpressionProfiles.Rd
index e41492d..8c0ff59 100644
--- a/man/plotExpressionProfiles.Rd
+++ b/man/plotExpressionProfiles.Rd
@@ -32,6 +32,7 @@ exampleCAGEexp |> plotExpressionProfiles("consensusClusters")
 }
 \seealso{
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{hanabiPlot}()},
 \code{\link{plotAnnot}()},
 \code{\link{plotCorrelation}()},
diff --git a/man/plotInterquantileWidth.Rd b/man/plotInterquantileWidth.Rd
index a4a04a1..ace83a0 100644
--- a/man/plotInterquantileWidth.Rd
+++ b/man/plotInterquantileWidth.Rd
@@ -63,6 +63,7 @@ plotInterquantileWidth( exampleCAGEexp, clusters = "consensusClusters"
 }
 \seealso{
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{hanabiPlot}()},
 \code{\link{plotAnnot}()},
 \code{\link{plotCorrelation}()},
diff --git a/man/plotReverseCumulatives.Rd b/man/plotReverseCumulatives.Rd
index ddd8dfb..13b6c2b 100644
--- a/man/plotReverseCumulatives.Rd
+++ b/man/plotReverseCumulatives.Rd
@@ -101,6 +101,7 @@ expression data: constructing the human and mouse promoterome with deepCAGE data
 \code{\link{normalizeTagCount}}
 
 Other CAGEr plot functions: 
+\code{\link{TSSlogo}()},
 \code{\link{hanabiPlot}()},
 \code{\link{plotAnnot}()},
 \code{\link{plotCorrelation}()},
diff --git a/vignettes/CAGEexp.Rmd b/vignettes/CAGEexp.Rmd
index 8495090..f493999 100644
--- a/vignettes/CAGEexp.Rmd
+++ b/vignettes/CAGEexp.Rmd
@@ -340,6 +340,19 @@ corr.m <- plotCorrelation2( ce, samples = "all"
                           , method = "pearson")
 ```
 
+### Sequence distribution at the transcription start site.
+
+The presence of the core promoter motifs can be checked with the `TSSlogo()`
+function, provided that the _CAGEexp_ object was built with a _BSgenome_
+package allowing access to the sequence flanking the transcription start sites.
+
+```{r TSSlogo, fig.cap="Sequence logo at the transcription start site"}
+TSSlogo(CTSScoordinatesGR(ce) |> subset(annotation == "promoter"), upstream = 35)
+```
+
+The `TSSlogo()` function can also be used later.  When passed _tag clusters_
+or _consensus clusters_, it will automatically center the regions on their
+_dominant peak_.
 
 Merging of replicates
 ---------------------