CYP2A6 and cancer: Demographics additionally affect the activity of the CYP gene family, as CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, and CYP3A4/5 are known to have higher activity in older adults, while allelic variations may correlate with increased susceptibility to cancers (breast, lung, prostate, etc.)or nicotine (CYP2A6*2 1799T > A) metabolism [31].