BCL2 and neoplasm: In accordance, clonal expansion of tumor populations harboring mutations in genes with established potential in lymphoma was observed in rrDLBCL tumors, noting expansion in clonal frequency of populations with ATM, B2M, BCL2, CD79B, CREBBP, KMT2D, SOCS1, STAT6, and TP53 mutations (Fig. 5E).