The expression phenotype of murine APL cells. (A) Unsupervised hierarchic clustering analysis of RNA array data (32 420 probe sets) from the spleens and bone marrows of 4 independent mCG-PML-RARα mice with APL, 4 normal murine bone marrow samples, and 2 normal murine spleen samples. Expression data on the heat map are displayed as z-scores. (B) Expression levels of 12 genes associated with early, mid, and late myeloid differentiation (during murine G-CSF–induced differentiation, days 0-1: blue bars; days 2-3: pink bars; days 4-7: blue-green bars), and in 6 murine APL samples (red indicates averages for 6 samples; brackets, SEMs). (Inset) Expression levels of PU.1 on an expanded scale. (C) Heat map of expression data from set 1, and 6 independent APL samples. Probe sets (4244) with expression values peaking on day 2 were selected for analysis. Expression is shown as a ratio of each sample to the reference sample (day 2). Data from the same differentiation experiment (set 1) were displayed in panels B-C.