The progression of normal pancreatic ductal epithelial cells into PanINs and adenocarcinoma is associated with alternation in expressions of oncogene and tumor suppressor genes [39], such as Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), cyclin-dependent kinase inhibitor 2A [40,41] (CDKN2A), tumor protein p53 (TP53), and mothers against decapentaplegic homolog 4 (SMAD4). Here, CDKN2A is linked to adenocarcinoma.