Genes differentially expressed between early and late relapse in patients (n = 54) with precursor B-ALL. (A) Patients were classified into 2 groups—early relapse (< 36 months from diagnosis) and late relapse (≥ 36 months)—using binary classification: 114 probe sets were chosen by SAM, with an FDR of 2.5% or less. (B). A linear regression model of survival analysis was used to show the possible association of the gene expression values with time to relapse. A number of probe sets (118) were chosen, with an FDR of 1.5% or less. (C) Functional categorization: 263 probe sets that were differentially expressed between early and late relapse with an FDR less than 5% were grouped according to function using the GeneOntology Biological Process classification. Yellow bars represent the number of genes relatively overexpressed, and blue bars represent genes relatively underexpressed at relapse.