Matson et al. (2018) analysed gut microbiota in metastatic melanoma patients and found that Bifidobacterium longum, Collinsella aerofaciens and Enetrococcus faecium were much more abundant in metastatic melanoma patients who responded well to anti-PD-1/anti-PD-L1 immunotherapy [17]. The gene discussed is CD274; the disease is metastatic melanoma.