PDCD1 and cancer: The treatment of cancer coexisting with TB is a complex process: on the one hand, blood toxicity and liver toxicity associated with anti-TB drugs overlap with the adverse reactions of cytotoxic chemotherapy drugs, and the optimal time of drug administration has not been determined; on the other hand, PD-1 blockade has been observed to exacerbate M. tuberculosis infection in animal experiments (25), and it is difficult to predict whether ICIs will also cause TB infection outbreaks in patients with lung cancer complicated with TB.