SLCO1B1*15 is assigned no function based on strong evidence in heterozygous and homozygous patients, and in vitro studies. SLCO1B1*15 has been studied for more than 15 years and its association with impaired function compared to wildtype is well-established (21245207, 25350695, 31220337). Though in vitro, the *15 allele may have more function than the *5 allele, analyses of pharmacokinetics and statin-associated muscle symptoms are usually performed on the rs4149056 variant included in the *5 and *15 alleles, so the same functional status was assigned for each of these alleles.