In another study, Chaput et al., explored the relationship between the baseline gut microbiome and clinical response and GI toxicities in patients receiving Ipilimumab (CTLA-4) and reported that at baseline most of the colitis-associated phylotypes were related to Firmicutes (e.g., relatives of Fecalibacterium prausnitzii and Gemmiger formicilis) and that no colitis-related phylotypes were associated with higher level Bacteroidetes [21]. Here, CTLA4 is linked to colitis.