RB1 and CD4+/CD56+ hematodermic neoplasm: Remarkably, the significant association of these alterations (i.e., loss of CDKN2A-B/9p21, CDKN1B/12p13, or RB1/13q14, rearrangement of MYC/8q24 or MYB/6q23) constitute the special and unique pattern frequently detected in BPDCN (Table 1).