ABCB1 and stroke disorder: When the participants were divided into four groups on the basis of ABCB1 3435 C > T and CYP2C19 status, those who did not carry at-risk genotypes in either gene had a significantly lower rate of cardiovascular death, ACS, or stroke at 15 months compared to those who were either carriers of CYP2C19 LOF alleles, ABCB1 3435 TT homozygotes, or both (p = 0.0002).