IL23A and psoriatic arthritis: Clinical studies performed with antibodies targeting the p40 subunit of IL-12 and IL-23 (ustekinumab and briakinumab) or the p19 subunit of IL-23 (tildrakizumab and guselkumab) have been performed in patients with psoriasis, ankylosing spondylitis and psoriatic arthritis [168].