RNF31 (RING finger protein 31; HOIP; ZEBRA) was firstly discovered in 2004 from breast cancer MCF-7 cells, which contained several functional domains including ZNF-RBZ domain, UBA (Ubiquitin binding associated) domain and RBR (RING-IBR-RING) domain [6]. This evidence concerns the gene RNF31 and breast cancer.