This cluster of papers focuses on hypersensitivity reactions to various drugs and medications, including the role of specific HLA genotypes such as HLA-B*5701, HLA-B*1502, and HLA-B*5801 in predicting severe cutaneous adverse reactions like Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis. The cluster also covers topics related to drug-induced hypersensitivity syndrome (DIHS), delayed drug hypersensitivity reactions, and the use of genetic screening to prevent abacavir hypersensitivity reactions.