β-sitosterol is a component of beans that has been shown to inhibit growth of COLO 320 DM cells (IC50 266.2 μM), by scavenging reactive oxygen species and inducing apoptosis; as well as suppressing the expression of β-catenin and PCNA antigens in human colon cancer cells [21,22]. This evidence concerns the gene PCNA and malignant colon neoplasm.