PRKCZ and head and neck squamous cell carcinoma: The associations between PRKCZ methylation status and patients’ sex, age, T stage, lymph node metastasis, and tumor recurrence were not significant (p = 0.3138, p = 0.4679, p = 0.2365, p = 0.5322, and p = 0.5827, respectively), whereas PRKCZ methylation status was significantly related to the pathological grading of HNSCC patients (p = 0.0386).