HLA-B and toxic epidermal necrolysis: As a prominent example, the occurrence of Stevens–Johnson syndrome and toxic epidermal necrolysis with use of carbamazepine was found to be very closely linked to the HLA-B*15:02 allele among Taiwanese residents,32 which was later replicated in Chinese, Indian, Malaysian and Chinese–American residents.33 However, this allele is largely absent in non-Asian individuals.33 The lack of an association between HCTZ use and skin cancer in an Asian population can have multiple explanations.