In contrast to the limited added value of JAK inhibitors to treat rheumatoid arthritis, the arrival of IL-17/23 inhibitors (i.e. ustekinumab, secukinumab, ixekizumab) meant an improvement in the treatment of psoriatic diseases (Nast et al., 2017; Kerschbaumer et al., 2020; Smolen et al., 2020; Torres et al., 2020). Here, IL17A is linked to rheumatoid arthritis.