HLA-B and Stevens-Johnson syndrome: Individuals may lack naïve T-cell specificities capable of responding to the new drug peptide target as has been recently demonstrated for HLA-B*15:02 associated Stevens-Johnson syndrome/toxic epidermal necrolysis where a specific TCR clonotype is prevalent amongst HLA-B*15:02 positive cases but not in HLA-B*15:02 positive carbamazepine tolerant controls [33].