CCDC6 and head and neck squamous cell carcinoma: By contrast, the CCDC6 expression levels in glioblastoma multiforme (p<0.001), head and neck squamous cell carcinoma (p<0.01), kidney chromophobe (p<0.001), kidney renal clear cell carcinoma (p<0.05), kidney renal papillary cell carcinoma (p<0.01) and thyroid carcinoma (p<0.001) were lower than those in the corresponding control tissues.