PRF1 and vitiligo: Some cytokines such as KLRG1+ lymphocytes secrete cytotoxic molecules (granzyme B and perforin), inflammatory cytokines (IFN-γ and TNF-α), and inflammatory chemokine receptors (CCR5 and CX3CR1) are involved in gene expression, which are associated with vitiligo (Li et al., 2019).