The efficacy of FMT as an anti- cancer therapy still under studies in conjugation with immune checkpoint blockade inhibitors like anti- PD1/PD-L1 or anti- CTLA4 antibodies (142–145) and are in different phases of clinical trials (NCT03353402, NCT03341143, NCT03772899, NCT03819296, NCT04577729, NCT04116775, NCT04758507, NCT04951583, 04988841, NCT05286294, NCT05279677, NCT0438619, NCT05008861, NCT04521075, NCT03819296, NCT05251389). This evidence concerns the gene CTLA4 and cancer.