HLA-DRB1 and adverse effect: In comparison to these existing predictive tests, the NPV of HLA-DRB1*04:02 (99.3%) is higher than the NPV of HLA-B*15:11 and HLA-B*57:01 genotyping for carbamazepine (98.9%) [46] and abacavir (82%) [47] hypersensitivity reactions, respectively, and about the same as the HLA-B*58:01 test (99.0%) for allopurinol-induced severe cutaneous adverse reactions (SCARs) [48].