Using quantitative real-time PCR, our group demonstrated that H508, WiDr, and Caco-2 human colon cancer cell lines all express ChAT, that H508 and Caco-2 cells release ACh into cell culture media, and that muscarinic receptor antagonists inhibit proliferation of unstimulated H508 cells by about 40% [39]. This evidence concerns the gene CHAT and malignant colon neoplasm.