HLA-C and psoriasis: Three of the identified psoriasis risk variants had a stronger association with PsC than PsA (rs12189871 near HLA-C, rs4908742 near TNFRSF9, rs10888503 near LCE3A), whereas two had a stronger association with PsA than PsC (rs12044149 near IL23R, rs9321623 near TNFAIP3) [8].