Tumour tissue from these mice (hereafter referred to as Kras p53R172H) was studied, along with tumour tissue from Pdx1-Cre; LSL-KrasG12D/+; LSL-Trp53flox/+ (Kras p53flox) mice and Pdx1-Cre; LSL-KrasG12D/+; Ptenflox/+ (Kras Ptenflox) mice, both of which develop PDACs that rarely metastasise6,11. Here, KRAS is linked to neoplasm.