A clinical trial evaluated the safety and efficacy of responder-derived FMT together with anti-PD-1 in patients with PD-1-refractory melanoma to investigate whether resistance to anti-PD-1 can be overcome by changing the gut microbiota.[11] Here, an increase in taxa was associated with responses to anti-PD-1, increased CD8+ T cell activation, and decreased frequency of interleukin-8 expressing myeloid cells. This evidence concerns the gene CD8A and melanoma.