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). The gene discussed is B2M; the disease is lymphoma.