I-E TIMEs are densely packed with immune cells but devoid of cytotoxic lymphocytes (CTLs) in the tumor core, whereas I-I TIMEs are densely packed with CTLs expressing programmed cell death 1 (PD-1), and leukocytes and tumor cells within I-I TIMEs express immune-dampening PD-1 ligand (PD-L1). This evidence concerns the gene PDCD1 and neoplasm.