In our own transgenic murine model of activating transcription factor 6 (ATF6)-induced microbiota-dependent CRC (nATF6IEC), we showed a loss of mucin-filled goblet cells and a more penetrable mucus layer already preceding tumor formation in the colon of homozygous nATF6IEC mice [105]. This evidence concerns the gene MUC5AC and colorectal carcinoma.