CCL22 and vitiligo: In 2010, Klarquist J et al4 first reported that the percentage of Tregs among skin infiltrating T cells drastically reduces in non‐lesional, perilesional and lesional skin from vitiligo patients, which was further supported by many other subsequent researches.5, 6 Moreover, increasing the abundance of Tregs by CCL22 overexpression can reduce depigmentation in two mouse models of vitiligo,7 indicating that replenishing Tregs can repair the disrupted autoimmune tolerance and is a promising treatment for vitiligo.