Recently, one of the chromatin-associated snoRNA subsets was found to be relevant to DNA damage and cancer genome instability; notably, among them, the orphan snoRNA SNORA73 can combine poly (ADP-ribose) polymerase 1 (PARP1) and the canonical H/ACA proteins DKC1/NHP2 to form a snoRNP at DNA damage genomic loci, which blocks PARP1 autoPARylation and DNA damage repair and leads to genome instability and cell differentiation in AML [145]. Here, PARP1 is linked to cancer.