PDCD1 and cancer: In particular, FMT has a long history of clinical application and was used as a standard-of-care for recurrent Clostridioides difficile infection (rCDI) in many countries.21–23 In limited studies, FMT has also been shown to improve anti-programmed cell death protein 1 (anti-PD-1) response in immunotherapy-refractory cancer patients,24,25 indicating that targeting the microbiome is a promising way to improve the efficacy of precision cancer therapy.