Association of catalase or GPX levels with IGHV status, BCR signaling, and clinical behavior. (A) Expression levels of catalase or GPX in mutated (M) and unmutated (UM) IGHV CLL (n = 26). *P ≤ .05; **P ≤ .01 (B) Association between phosphorylation responses to BCR modulation and catalase or GPX expression levels. BCR signaling in response to anti-IgM stimulation was measured as the log2-fold change of ERK1/2 phosphorylation between anti-IgM-modulated and unmodulated conditions (n = 11). For each comparison is indicated the Pearson correlation coefficient along with the probability value for the null hypothesis of no correlation. (C) Kaplan-Meier curves of TTFT for subgroups of patients with CLL, defined by expression levels of catalase or GPX (n = 26). High and low enzyme expression values were referred to the median expression values. P values are from the logrank test.