It was reported that there is some discrepancy in different passage of mouse models, for instance, Metildi et al26 ever reported that serially passaging in vivo generated more aggressive variants of both human pancreatic cancer cell lines, one of which was Kras wild‐type (BXPC‐3) and the other Kras mutant, Panc‐1, which displayed faster tumour growth and shortened survival time. This evidence concerns the gene KRAS and pancreatic neoplasm.