The expression of aquaporin 3 (AQP3) in vitiliginous keratocytes (KCs) and its role in KC survival was studied. AQP3 expression was significantly decreased in depigmented versus pigmented epidermis in vitiligo patients (P < 0.001). Transfection of cultured normal human KCs with AQP3 decreased the expression of several downstream signaling molecules including phosphorylated P13K, e-cadherin and beta and gamma-catenin. These were also decreased in depigmented epidermis. Decreased AQP3 in vitiliginous KCs may be responsible for their decreased survival in vitiligo (Kim, N. and Lee, A-Y. J Invest Dermatol 2010, 130: 2231).