In addition to PD-L1 expression, CD8 T cells distinctly at the tumor margin [16], the presence of PD-1 + CD8 + T cells in tumors [17] and high densities of CD45 + T cells have been linked to a clinical benefit from PD-1 blockade based on pretreatment tumor specimens [18]. The gene discussed is PTPRC; the disease is neoplasm.