GSTP1 and malignant colon neoplasm: Especially, pi-class GSTs including GSTP1 are overexpressed in a variety of cancers, including ovarian, breast, colon, and pancreatic cancers [15], and the preclinical studies using human colon cancer cell lines lacking GSTP1 have shown that GSTP1 is important for the survival and growth of human colon cancer cells [16].