CEBPA^sil leukemias differ genetically and epigenetically from T-ALL. (A) Principal component analysis of DNA methylation data comparing 8 immature acute myeloid/T lymphoid CEBPA^sil cases with a selection of 9 T-ALL cases representing a spectrum of maturation stages, showing separate clustering of the 2 groups of leukemias. (B) Two-dimensional hierarchical clustering of genes differentially methylated between the CEBPA^sil leukemias and the T-ALL cases, illustrated by a heatmap. Cases are represented in the columns; probe sets are represented in the rows. Supervised analysis identified 213 differentially methylated probe sets (199 genes). CEBPA^sil cases are clustered in the left node and display a predominance of hypomethylated probe sets. (C) Principal component analysis of gene expression data for the same cases also demonstrates separate clustering of the 2 groups of leukemias, indicating that these 2 groups display distinct expression profiles.