PDCD1 and cancer: In addition, we also found that MS-20 regulated the microbial composition in the feces of cancer patients ex vivo, where the enrichment of bacteria and their predicted metabolic activities may resemble the gut microbiota profile of individuals who respond to immunotherapy.37 Briefly, MS-20, a fermented soybean extract, enhanced the efficacy of the anti-PD1 antibody through the regulation of complex interactions between the microbiota and immune cells and intestinal cells.