SLC22A3 and asthma: Yamauchi et al. reported that four major genetic polymorphisms (S116A, R120R, I140T, and A411A) of the OCT-3 gene including synonymous alterations were investigated concerning the relationship between the allele frequency and asthma severities, and were classified into two groups (mild and moderate/severe) on the basis of the Japanese asthma severity guidelines.