CYP2C9 and pulmonary hypertension, primary, 1: In the current study, the CYP2C9*3 (AC) genotype was found in 12 out of 25 PHT-CADRs cases, but only two patients in the PHT-tolerant group had this allele, and the homozygous (CC) genotype was not found in either case or the tolerant control group (Table 3).