Notably, baseline enrichment in Bacteroidetes phylum (includes Bacteroides thetaiotamicron and Bacteroides caccae) has been associated with response to anti-PD-1 and anti-CTLA-4 therapy in melanoma patients [25], which is in contrast to some preclinical and clinical evidence described previously that support their abundance as associated with lack of response. This evidence concerns the gene CTLA4 and melanoma.