Moreover, Matson et al. [74] evaluated the baseline stool samples from patients with metastatic melanoma before PD-1/PD-L1 blockade treatment, and the results showed that commensal microbial composition was significantly associated with the clinical response: Bifidobacterium longum, Collinsella aerofaciens, and Enterococcus faecium were more abundant in responders. This evidence concerns the gene CD274 and metastatic melanoma.