CYP2C9 and pulmonary hypertension, primary, 1: In Asian populations, HLA B*51:01 has been related to PHT-induced CADRs, particularly with PHT-SCARs [40,41].A recent multicenter East Asian study that investigated the genetic predictors of PHT-hypersensitivity reported that concurrent testing of HLA B* 13:01/HLA B* 15:02/HLA B*51:01 and CYP2C9*3 would help in identifying individuals at risk of developing PHT-CADRs [42].