In this study PD-1, TIM-3, LAG-3, CTLA-4 and PD-L2 were significantly upregulated on tumour-infiltrating T cells compared with peripheral circulating T cells in OAC patients, which might reflect a more exhausted T cell phenotype mediated by IC-intrinsic signalling in the tumour microenvironment. Here, HAVCR2 is linked to neoplasm.