Nearly 2-5% of patients with Crohn's disease and RA receiving anti-TNF-α mAbs (infliximab, adalimumab and etanercept) were associated with an increased risk of paradoxical psoriasis due to prolonged type I interferon production by immature plasmacytoid dendritic cells (pDCs) in the dermis 10,12. The gene discussed is TNF; the disease is psoriasis.