Whether a tumor should be treated with chemotherapy or PD1 first depends on the pathological type of the tumor, the patient’s physical condition, the tumor load and other comprehensive judgments. Take lung cancer as an example, if, for example, PD1 or PDL1 is highly expressed and the patient’s physical condition is relatively good, PD1 or PDL1 inhibitors, such as pablizumab, can be used in the first line. If the expression level of PD1 or PDL1 is low, the first-line use of PD1 or PDL1 inhibitors alone at this time will not be very effective and need to be combined with chemotherapy or combined with anti-tumor angiogenesis drugs and other cases to achieve better results. If there is a genetic mutation, it is better to use targeted drugs against the genetic mutation than to use PD1 or PDL1 shift agents. In conclusion, whether to start with chemotherapy or PD1 inhibitor should be judged according to the actual situation.