ZAP70 and B-cell chronic lymphocytic leukemia: When stratified into quartiles by MTCP1 expression we observed a similar distribution between sexes and high-risk CLL cofactors including age, performance status, cytogenetic evaluation, IgHV mutation status, and Zap-70 methylation; with the exception of elevated blood lymphocyte counts (WBC) and advanced Rai stage at diagnosis skewing towards patients with higher MTCP1 expression (Q2-4).