This article reviews the recent literature on PRs associated with TNF-α, interleukin (IL)-12/23 (p40), IL-17A/the IL-17 receptor (R), IL-23 (p19), and IL-4Rα inhibitors, which are commonly used for dermatological conditions, especially atopic dermatitis (AD) and psoriasis. The gene discussed is IL4R; the disease is psoriasis.