Accordingly, recent studies demonstrated the existence of anti-PD-(L)1 therapy-responding T cell subsets in circulation (6, 7); 2) A previous theory suggested that activated T cells infiltrate the tumor, become dysfunctional, and finally die within tumor microenvironment (TME); however, recent research indicates that some tumor-infiltrating T cells can escape from the tumor and re-enter circulation (8). This evidence concerns the gene CD274 and neoplasm.