IL-23, one member of the IL-12 cytokine family, is crucial in the pathogenesis of psoriasis, experimental autoimmune encephalomyelitis (EAE), collagen-induced arthritis (CIA), inflammatory bowel disease (IBD) (Tonel et al., 2010; Teng et al., 2015) and leukocyte adhesion deficiency type 1 (LAD1) (Moutsopoulos et al., 2017). The gene discussed is LAD1; the disease is psoriasis.