As an example, the FDA's “boxed” warning on the package insert of the anticonvulsant drug carbamazepine, it recommends that prior to prescribing physicians should screen patients of Asian ancestry for the MHC-I human leukocyte antigen-B HLA-B*1502 allele, due to the increased risk of fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) (96). This evidence concerns the gene HLA-B and Stevens-Johnson syndrome.