Patients with B-cell malignancies are recommended to undergo genetic examinations for following mutations before the initiation of treatment or in cases of poor prognosis: (1) MCL: detection of TP53 mutation; (2) CLL/SLL: detection of del(11q), del(17p)/TP53 deletion or mutation and IGHV mutation status, and so on; (3) WM: detection of MYD88 L265P and CXCR4 WHIM mutation; (4) DLBCL: detection of MYD88 L265P, CD79b, bcl-6, bcl-2, Notch1/2 and myc mutations [140]. The gene discussed is NOTCH1; the disease is mantle cell lymphoma.