We detect EZH2 mutations in a significant proportion of BCL2-rearranged follicular lymphomas, BCL2-rearranged diffuse large B cell lymphomas, and high-grade B cell lymphomas with concurrent BCL2 and MYC rearrangements (so-called “double-hit lymphomas”), but not in BL. This evidence concerns the gene BCL2 and diffuse large B-cell lymphoma.