In particular, SIRT5 mRNA levels are increased in some cancers such as NSCLC, colorectal cancer (CRC), and Waldenstrom’s macroglobulinemia [66,114,115], while they are significantly decreased in others, including endometrial carcinoma and head and neck squamous cell carcinoma (HNSCC) [63,116,117]. This evidence concerns the gene SIRT5 and head and neck squamous cell carcinoma.