M3 is the main receptor in most colon cancer cells and has been associated with colorectal cancer progression [113,136], when these receptors are overexpressed; they can establish communication with some growth-regulatory pathways [137,138] and induce matrix metalloproteinase-1 (MMP1), involved in processes such as metastasis [139]. This evidence concerns the gene MMP1 and malignant colon neoplasm.