Analyzing of stool samples from renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC) patients after treating with PD-1 blockade revealed that clinical outcomes were associated with the abundance of Akkermansia muciniphia, oral supplementation with Akkermansia muciniphia to non-responders restored the efficacy of PD-1 blockade, which demonstrated that the Akkermansia muciniphia can enhance the effect of PD-1 inhibitor (Table 1) (20). Here, PDCD1 is linked to renal cell carcinoma.