PDCD1 and melanoma: Eight species (Bifidobacterium adolescentis, Enterococcus faecium, Collinsella aerofaciens, Bifidobacterium longum, Klebsiella pneumoniae, Veillonella parvula, Lactobacillus, and Parabacteroides merdae) were more abundant in the microbiome of the patients suffering from unresectable melanoma, non-small cell lung cancer, urothelial cancer, or renal cell carcinoma, who responded to anti-PD-1 therapy.