Compared to systemic ABC-DLBCL and GCB-DLBCL of which the copy number profiles reflected previously published results34,60,95, PCNSL demonstrated significantly more CN losses in 6p21 (HLA-D locus, Fig. 4a–c, Supplementary Data 8) as well as recurrent losses in 9p21 (MTAP, CDKN2A/B) and 19p13 (CDKN2D). The gene discussed is CDKN2A; the disease is aneurysmal bone cyst.