RNF2 and familial pancreatic carcinoma: In order to determine the expression of Bmi1 and Ring1b and the presence of H2AK119ub in pancreatic cancer development, we took advantage of Ptf1aCre/+;LSL-KrasG12D/+;Trp53lox/+ (KPC) mice, which develop pancreatic cancer within a short time frame.