PCNA and adenocarcinoma: We also examined the effect of folic acid supplementation on proliferation (PCNA), apoptosis (PARP, caspase-3, BAX, BCL-2, and BCL-XL), and mammary carcinogenesis (ERα and HER2) by determining the expression of several proteins involved in these processes in carefully selected representative sentinel adenocarcinomas from each diet group.