TIMP3 and head and neck squamous cell carcinoma: Salivary DNA methylation levels for RASSF1α, p16INK4a, TIMP3 and PCQAP/MED15 were higher in HPV-negative HNSCC patients (n = 88) compared with a normal healthy control group (n = 122) (sensitivity of 71 % and specificity of 80 %).