129, 130, 131 In patients with metastatic melanoma, treatment response to anti-PD-1 therapy was associated with a broader overall diversity of commensal bacteria and an increased relative abundance of Faecalibacterium,130 and in patients treated with anti-CTLA-4 antibodies, enrichment of Faecalibacterium was associated with significantly longer PFS/OS129. Similarly, abundance of A. muciniphila was positively associated with a treatment response in patients with multiple advanced cancers.131. This evidence concerns the gene CTLA4 and metastatic melanoma.