The melanocytorrhagy theory is based on the observation that mechanical friction leads to melanocyte detachment and transepidermal loss, suggesting that an impaired melanocyte adhesion may be the first step in the development of vitiligo.2, 4, 5 E-cadherin is a Ca2+ dependent transmembrane protein and a key adhesion molecule mediating melanocyte-keratinocyte interactions.3 The gene discussed is CDH1; the disease is vitiligo.