PRF1 and vitiligo: Of the other three studies, depending on transgenic mice with tyrosinase‐specific T cell clone,167 transgenic mice carrying T cells with an HLA‐A2 restricted human tyrosinase reactive T cell receptor (TCR)168 and mice manifesting melanoma‐induced autoimmune symptoms (vitiligo‐like white coat),143 respectively, the former two regard perforin as an unnecessary mechanism in melanocyte destruction.