PDX1 and pancreatic neoplasm: Rhim et al. generated an Shh-knockout PDAC mouse model by crossing an Shh-floxed allele into the Pdx1-Cre;LSL-KrasG12D/+;p53flox/+;LSL-Rosa26YFP/+ (KPCY) model of pancreatic cancer, resulting in the loss of Shh-dependent stroma throughout tumor progression [95].