Propionate is an HDAC inhibitor which inhibits malignant transformation and induces the apoptosis of precancerous colonic cells, despite its poor effectiveness (in comparison to butyrate) and reduced abundance in CRC.[134] Finally, formate secreted by F. nucleatum, can drives CRC tumor invasion by triggering Aryl hydrocarbon receptor signaling, while increasing cancer stemness.[135] Formate can be considered a gut‐derived oncometabolite relevant for CRC progression. The gene discussed is HDAC9; the disease is colorectal carcinoma.