Adapalene is a derivative of tretinoin that is clinically used to treat acne and pityriasis versicolor. This synthetic retinoid exhibits anti-inflammatory activity, decreasing expression of Ki67, α2-integrin, α6-integrin, toll-like receptor 2 (TLR2), IL-8, and β-defensin in ex vivo models. Like other retinoids, adapalene also activates retinoic acid receptors RARα/β/γ across several models.