HLA-B27 is strongly asspciated with ankylosing spondylitis (AS), and other associated inflammatory diseases referred to as “spondyloarthropathies”. HLA-B15 Marker for carbamazepine induced Stevens-Johnson-Syndrome. HLA-B*58:01 is risk factor for allopurinol-induced DRESS and Stevens-Johnson syndrome/toxic epidermal necrolysis in a Portuguese population. HLA-B*5708 is associated with hypersensitivity to allopurinol used to treat hyperuricemia and recurrent gout. HLA-B*5701 is strongly associated with hypersensitivity to the HIV drug abacavir, liver toxicity from the antibiotic flucloxacillin and is a marker for slow progression of HIV AIDS.