PRKD1 and head and neck squamous cell carcinoma: This is a novel interesting finding that unlike other reports showing a significant functional role that associates with altered PKD1 expression in different tumors, our data indicate that PKD1 has limited functional impact in the proliferation, survival, migration, and invasion of HNSCC cells at the basal state, despite frequent downregulation of PRKD1 transcript and protein expression in HNSCC tumors and cell lines.