2022). However, only around a hundred of those have been associated with IDRs. The most well‐established risk alleles are HLA‐B*57:01 for abacavir hypersensitivity syndrome (ABC‐HSS), HLA‐B*15:02 and HLA‐A*31:01 for carbamazepine‐induced SJS/TEN, and HLA‐B*58:01 for allopurinol‐induced SJS/TEN or drug rash with eosinophilia and systemic symptoms (Pavlos et al. 2015). The gene discussed is HLA-B; the disease is toxic epidermal necrolysis.