Unsupervised clustering analysis of DNA methylation in infant ALL. PCA of the CpG island methylation data from infant ALL patients and normal bone marrows using all probes present on each microarray platform. Each case is color-coded, indicating the specific infant ALL subgroups. (A) Data from the custom-spotted 9K CpG island microarray. t(4;11) (n = 21; red), t(11;19) (n = 17; orange), t(9;11) (n = 6; yellow), MLL wild-type ALL (n = 13, green), and normal bone marrow (n = 8; blue). (B) Data from the commercially available 244K CpG island microarray (Agilent). t(4;11) (n = 16; red), t(11;19) (n = 15; orange), t(9;11) (n = 6; yellow), MLL wild-type ALL (n = 12; green), and normal bone marrow (n = 7; blue). Because of restricted availability of patient material, Agilent DNA methylation profiles were generated for 49 infant ALL patients and 7 normal bone marrow samples.