Researchers have also used a combination of 11 rare microbial species to support the anti-cancer effect of anti-CTLA-4 and anti-PD-1 immunotherapies in mouse models of adenocarcinoma and melanoma, leading to a decrease in tumor volume.133 In mice monocolonized with different species of bacteria, those that were colonized with Bifidobacterium pseudolongum, L. johnsonii, or Olsenella spp. The gene discussed is CTLA4; the disease is cancer.