Membrane protein abundance changes in AML cells after ATRA stimulation. (A) Hierarchical cluster analysis of log2 protein ratios of 165 membrane proteins that were identified in both AML cell lines by the MS-based CSC technology. Each row represents the abundance changes of 1 membrane protein after ATRA stimulation and each column represents 1 AML cell line. Red indicates increased protein abundance, while green indicates decreased protein abundance after ATRA stimulation. (B) Protein cluster number 1 contained membrane proteins, which showed decreased protein abundances in both AML cell lines after ATRA stimulation. Names of proteins are shown next to the heat map and if applicable CD numbers are included. Numbers in brackets are the number of peptide identifications used for quantification of the protein in HL60 (first number) and in NB4 cells (second number), respectively. (C) Protein cluster number 3 contained membrane proteins, which showed increased protein abundances in both AML cell lines after ATRA stimulation.