PDCD1 and neoplasm: Although proliferating CD4+ T cells (median 1.24 and 1.00 cells per mm2 in tumor and stroma, respectively, p = 0.888) and PD1+ CD4+ T cells (median 1.05 and 0.46 cells per mm2 in tumor and stroma, respectively, p = 0.180) were slightly more abundant in the tumor parenchyma, these small differences failed to reach statistical significance.