KMT2B and mantle cell lymphoma: Other small studies investigating CDKN2A, NOTCH1 and/or NOTCH2 mutations, MYC overexpression, KMT2B mutations, NSD2 mutations, CCND1 mutations, and/or ATM mutations have also suggested poorer prognosis in patients with MCL, although these studies are limited [11,39,40,41,42,43,44].