TTK and head and neck squamous cell carcinoma: To determine mRNA expression levels of the seven hub genes (CNFN, KIF18B, KIF23, PRC1, CCNA2, DEPDC1, and TTK), we used GEPIA and found that CNFN was significantly downregulated but KIF18B, KIF23, PRC1, CCNA2, DEPDC1, and TTK were significantly upregulated in HNSCC (P < 0.05; Fig. 6i).