CYP2C19*1 is assigned normal function based on definitive evidence. CYP2C19*1 has been studied for more than 20 years and is the most frequently observed allele (7487078, 32602114). CYP2C19*1 has repeatedly demonstrated normal function with numerous substrates and its association with normal function is well-established (22027650, 29325448, 33237321).