With a bioactive and selective inhibitor of CBS in hand, we examined the effect of CH004 on the proliferation of HepG2 and HEK293T cells as well as hepatocellular carcinoma Huh7 and H22, pancreatic cancer Panc-28, colon cancer HCT116 and breast cancer MDA-MB-231 cells. The gene discussed is CBS; the disease is breast carcinoma.