In a further innovative study, Routy et al. examined the relationship between the baseline gut microbiome and the clinical response of patients with NSCLC (n = 78) and RCC (n = 40) during ICIs (PD-1) treatment and reported that the relative abundance of Akkermansia muciniphila in fecal samples of both cancer groups before ICIs, was positively correlated with PFS and OS. This evidence concerns the gene PDCD1 and renal cell carcinoma.