However, conditional deletion of Shh results in more aggressive, undifferentiated tumors in a pancreatic cancer mouse model (Pdx1-Cre; lox-stop-lox-KrasG12D/+; Trp53lox/+; Shhlox/lox; lox-stop-lox-YFP-Rosa26) [38]. The gene discussed is PDX1; the disease is familial pancreatic carcinoma.