The Harward algorithm not only “invented” a novel group of low-risk ABC-DLBCLs but also divided GCB cases into two distinct subsets, C3 and C4, each with a different outcome; there was also a group that could not be related to the ABC/GCB division, and their hallmarks were biallelic inactivation of TP53, loss of CDKN2A, and associated genomic instability. Here, CDKN2A is linked to aneurysmal bone cyst.