And in the mucosa of carcinoma-bearing mice, significant increased Proteobacteria became dominant at the phylum level, with decreased percentage of Firmicutes. However, the MyD88 inhibitor treatment led to almost undetectable Proteobacteria in the mucosa and the retention of the dominance of Firmicutes and Bacteroidota at phylum level. The gene discussed is MYD88; the disease is carcinoma.