PIK3CA and neoplasm: The results allow us to suggest that (1) the mutational profile in CMTs is similar to HBC related to tobacco carcinogens, (2) PIK3CA (A3140G: H1047R) mutation and its signaling pathway is a major driver mutation in CMTs, (3) the comparative approach for HBC using CMTs is very useful to identify novel mutations and genes which might be associated with HBC, and (4) further functional studies will be necessary for the missense mutations on these genes in diverse tumorigenesis and tumor malignancy.