SHPRH is a member of the SWI/SNF family of ATPaes/helicases, it posesses a C3HC4 RING motif characteristic of ubiquitin ligase protein and it has a fundamental role in DNA repair mechanism. Upon genotoxic stress, SHPRH associates with PCNA, RAD18, and the ubiquitin-conjugating enzyme UBC(E2) and promotes methyl methanesulfonate (MMS)-induced PCNA polyubiquitation suppressing genomic instability. SHPRH gene is mutated in a number of cancer cell lines, including those from melanomas and ovarian cancer.