The function of ERβ at the molecular level was investigated in vitro by Hartman et al. They used SW480 colon cancer cells transduced by lentivirus plasmid carrying ERβ; its exogenous over-expression induced a blockage in cell proliferation and cell cycle arrest in the G1 phase, with a reduction in the expression of the oncogene c-Myc (overexpressed in CRC) compared to controls. This evidence concerns the gene ESR2 and malignant colon neoplasm.