ERAP1 and psoriasis: Therefore, ERAP1 SNPs have been correlated with HLA-associated diseases like ankylosing spondylitis (AS) (20), psoriasis (21, 22), type 1 diabetes (T1D) (23), inflammatory bowel disease (24), Behçet’s disease (25), cervical cancer (26), and hypertension (27), suggesting that ERAP1 polymorphisms can exert diverse effects.