CTLA4 and cancer: Next generation probiotics, such as Akkermansia muciniphila and Faecalibacterium genus as well as genetically modified microorganisms (GMOs) (O’Toole et al., 2017) have demonstrated beneficial effects in the context of cancer, promoting the immune checkpoints inhibitors therapy targeting the programmed cell death protein 1 (PD-1) and cytotoxic lymphocyte-associated antigen (CTLA-4).