PDCD1 and neoplasm: Conversely, one tumor (no. 3) was characterized by high immune cell densities (CD3+ at 654.2 per mm2; CD8+ at 244.4 per mm2, almost all PD1 negative; CD20+ at 37.3 per mm2), presence of TLS aggregate, and weak PD-L1 expression on both tumor cells and macrophages.