Promoter hypermethylation of Wnt antagonists in samples from patients with ALL. (A) MSP analysis of methylated (M) and unmethylated sequences (U) in patients (UPN) with ALL at diagnosis. PB C− indicates peripheral blood lymphocytes from healthy donors; BM C−, bone marrow mononuclear cells from healthy donors; C+, human male gDNA universally methylated for all genes (used as a positive control for methylated alleles). (B) Frequency of promoter methylation for each Wnt antagonist in a series of 261 patients with ALL at diagnosis. (C) Distribution of patients included in the study according to the number of methylated genes.