Preventive strategies may be essential and include rigorous oral hygiene measures with non-irritating, alcohol-free rinses; cryotherapy during 5-FU infusion, which has shown significant reduction in mucositis severity; and dexamethasone mouthwash prophylaxis during mTOR inhibitor therapy, which reduces the risk of severe stomatitis [106,190,191,193,211]. This evidence concerns the gene MTOR and stomatitis.