Pheatmap is a dedicated package in R language for creating beautiful heatmaps. It addresses many shortcomings of the basic R heatmap functions when generating publication-quality heatmaps, such as control over graphic size, consistency of text and cell sizes, etc. Pheatmap offers detailed graphic control options, including: direct control over cell size and text size, automatic generation of legends, row and column annotations, post-editing capabilities based on the grid graphics system, and visual segmentation of clusters using separators. This tool is widely popular for its simplicity and aesthetic output, and is commonly used as a tool for visualizing transcriptome expression matrices.