Antitumor immunity involves the complex interplay among immune, cancer, and cancer‐associated cells.[63, 64] Specific DNA‐ and histone‐modifying enzymes contribute to both the immunogenicity of cancer cells and the lineage commitment and/or maturation of immune cells.[65, 66, 67] Moreover, resistance to immune‐checkpoint inhibitors can be reverted by epigenetic manipulations in preclinical models.[64, 68] Thus, epigenetic drugs in combination with PD‐1 or PD‐L1 antibody can potentially improve therapy efficacy. The gene discussed is PDCD1; the disease is cancer.