PI3K-activated T-ALL cell lines and human ETP ALLs have similar gene expression profiles. (A) Principal component analysis of the gene expression profiling data of all 10 mouse T-ALL cell lines using 200 representative genes selected by k-means algorithm, showing cases clustered according to PI3K activation status (red, activated; blue, not activated). (B) Gene set enrichment analysis demonstrates significant enrichment of the top 100 mouse PI3K up-regulated genes in ETP ALL (P = .057; false discovery rate, 0.224). (C) Heat map of the leading-edge mouse PI3K up-regulated genes in gene set enrichment analysis, showing overexpression of these genes in ETP ALL.