Furthermore, patients with inherited IL-10RB deficiency whose cells do not respond to IL-22 (nor to IL-10, IL-26, IL-28, and IFNL1) do not develop CMC; a single case of treatment-responsive OPC in the absence of iatrogenic immunosuppression has been reported in IL-10RB–deficient patients (OPC frequency, ~3%) who develop very severe early-onset inflammatory bowel disease requiring treatment with corticosteroids and/or TNF-α inhibitors (121–123). This evidence concerns the gene IL10RB and inflammatory bowel disease.