Remarkably, the immunological consequences of NER defects are far less explored than those of MMR and BER, although people suffering from the NER defect disease, xeroderma pigmentosum (XP), had an impressive response of their skin tumors to anti-programmed cell death-1 (PD-1) ICI in case reports [2,5,6,7,8,9,10,11,12]. The gene discussed is PDCD1; the disease is xeroderma pigmentosum.