Preclinical and clinical studies have demonstrated that a human anti-IL-22-mAb (fezakinumab) and IL‐22R1‐targeting mAbs are currently tested as a treatment for several inflammatory diseases such as rheumatoid arthritis and severe atopic dermatitis, without obvious adverse safety concerns observed (Sabat et al. 2014; Kragstrup et al. 2018; Guttman-Yassky et al. 2018). This evidence concerns the gene IL22 and rheumatoid arthritis.