CD4 and neoplasm: The spatial relationships among PD1+CD4+ T cells, tumor cells, and regulatory T cells were quantified by a very simple and intuitive “spatial score.” Patients with a low spatial score, which indicates that PD1+CD4+ T cells are in closer proximity to tumor cells than to suppressive regulatory T cells, were more likely to respond to anti-PD-1 treatment than were patients with a higher spatial score [19].