A synthetic vitamin D derivative usually formulated for topical dermatological use, antipsoriatic calcipotriene (calcipotriol) competes equally with active 1,25-hydroxy-2D3 (the natural form of vitamin D) for 1,25-hydroxy-2D3 receptors in regulating cell proliferation and differentiation. It induces differentiation and suppresses proliferation of keratinocytes, reversing abnormal keratinocyte changes in psoriasis, and leads to normalization of epidermal growth. Check for active clinical trials using this agent.