AKR1A1 and head and neck squamous cell carcinoma: Cluster 1 enriched for cell cycle related genes including the MCM family of proteins, while Cluster 2 featured xenobiotic enzymes including those in the alcohol dehydrogenase (ALDH) and glutathione S transferase, both have been previously reported for HNSCC and OSCC [26, 27, 42, 49].