Table 1.

Biomarkers of response to check-point inhibitor immunotherapy that are also associated with vitiligo development.

Biomarker	Immunotherapy	Vitiligo
NLR	High NLR positively associates with response [85].	High NLR in patients with generalized disease [86].
PD-1/PD-L1	Expression of PD-L1 positively correlates with response [87,88,89].	High levels of PD-1 on CD8+ T cells positively associate with disease activity [90].
IFN-γ and IFN-related genes	Expression of CXCL-9, CXCL-10, CXCL-11 in the tumor microenvironment positively correlates with response [91].	High serum levels of CXCL-9 and CXCL-10 indicate vitiligo active phase [92].
Janus kinase (JAK)/signal transducers and activators of transcription (STAT)	JAK mutations are related to resistance to immunotherapy [93].	JAKs and STATs are over-expressed in vitiligo [94].
CTLA-4	High pretreatment expression of CTLA-4 in tumor tissue [88] or in tumor-infiltrating lymphocytes [95] positively correlates with response. Polymorphisms in the CTLA-4 gene are associated with response [96].	Polymorphisms in CTLA-4 gene are involved in vitiligo development [97].
Mismatch repair (MMR)	MMR deficiency positively correlates with response [98].	Vitiligo has been documented in patients with MMR defects [99,100].
microRNAs (miRNAs)	miR-146a, miR-155, miR-125b, miR-100, miR-let-7e, miR-125a, miR-146b, and miR-99b up-regulation predicts resistance to immunotherapy [101].	miR-155, miR-125b, and miR-let-7e are up-regulated in vitiligo [102,103,104].