We read with interest the article by Ostovari et al,1 who elegantly surmised that UV light is essential for tacrolimus to work. In our vitiligo clinic we have been studying the pattern of repigmentation of vitiligo with tacrolimus, the stability of this pigment, and the site variation for the last 2 years. We believe that there is sufficient evidence to show that tacrolimus monotherapy is useful to produce repigmentation.2