Thus, the use of nicotine or its derivatives has demonstrated the important role of distinct nAChR subtypes in the development of various types of cancer, such as α7 nAChR in lung, bladder and colon cancers [14,15,16,17], α9α10 nAChR in lung and breast tumors [17,18,19], as well as in gliomas, glioblastomas and melanomas (see review [20]), and the α3, α5, α7-containing receptors in pancreatic cancers [21]. Here, CHRNA4 is linked to cancer.