In this study, methyl-donor treatment (L-methionine, choline chloride, folic acid and vitamin B12) of an aggressive pancreatic adenocarcinoma cell line (Panc-1) resulted in significantly increased p21WAF1/Cip1 cyclin-dependent kinase inhibitor levels, along with apoptotic SubG1 fractions. The gene discussed is CDKN1A; the disease is pancreatic adenocarcinoma.