PDCD1 and neoplasm: Strauss et al. found that PD-1 in myeloid cells dampened antitumor immunity and demonstrated that myeloid cell PD-1 (PD-1fl/flLysMcre) ablation was as effective as global PD-1 (PD-1–/–) ablation in limiting tumor growth, and considerably more effective than lymphocyte PD-1 (PD-1fl/flCD4cre) ablation (27).