These include finding: (1) a cardinal mutation signature (BCL2, KMT2D, CREBBP, EZH2 and TNFRSF14) associated with FL development; (2) a mutation profile (MYC, GNA13, TP53, P2RY8, PIM1, CCND3, B2M, EBF1 and S1PR2) associated with FL high-grade transformation; and (3) frequent presence of a previous or concurrent FL in DLBCL with BCL2 translocation. This evidence concerns the gene BCL2 and diffuse large B-cell lymphoma.