Correlation of BIM epigenetic silencing with clinical outcome and with biologic features in BL. Kaplan-Meier curves for OS for (A) 36 patients with BL included in the study and (B) BL patients with methylated and unmethylated BIM, where BIM promoter hypermethylation was correlated with inferior CR rate (P = .002) and shorter survival duration (P = .007). (C) By MSP analysis, BIM hypermethylation was observed in 8 EBV⁺ BL cell lines and in 6 of 9 (66%) EBV-BL cell lines. By quantitative MSP analysis, measurement of BIM promoter hypermethylation according to EBV infection revealed higher hypermethylation levels in EBV⁺ lymphomas compared with EBV⁻ tumors (P < .01). (D) Correlation of box I MYC mutations in BL primary samples and cell lines with and without hypermethylation of BIM: mutations at box I from amino acid positions 57 to 60 (including Pro-57 and Thr-58 sites) were more frequent in BL cell lines and primary samples with BIM hypermethylation than in nonmethylated tumors (12 of 24 cases, 50% vs 6 of 16 cases, 37.5%; P = .19). (E) Western blot analysis of BCL2 family proteins in BL cell lines, classified in methylated and unmethylated BIM subgroups. β-Actin served as loading control. (F) Sequencing of P53 gene identified a lower number of mutations in patient samples with hypermethylated BIM with respect to unmethylated samples. Because almost all BL cell lines carried the P53 mutations, this analysis was restricted to primary tumors.