It was proposed by Sivan et al. that oral administration of Bifidobacterium, a particular taxon of microbial commensals, improved melanoma control to the same degree as programmed cell death protein 1 ligand 1 (PD-L1) specific antibody therapy (checkpoint blockade), and combination treatment nearly abolished tumor outgrowth in a mouse model [121]. This evidence concerns the gene CD274 and melanoma.