These include the first-in-class inhibitor for JAK 1–3/TYK2 (PF-06263276) in chronic plaque psoriasis (NCT01981681), dual TYK2/JAK1 inhibitor (PF-06673518, pre-clinical) and Tyk2/Jak1 (PF-06700841) for ulcerative colitis, CD, and psoriasis in phase II [340]. Here, TYK2 is linked to ulcerative colitis.