A pioneer to perform such an investigation was Viet et al. [38] who analyzed a panel of 1505 CpG loci in 807 cancer-related genes using tissue and saliva samples of OSCC patients and found a spectrum of genes involved in cell signaling (GABRB3, IL11, NOTCH3, NTRK3, and PXN), cell differentiation (IL11, NOTCH3, and NTRK3), development (INSR, NTRK3, and PXN), regulation of transcription (NOTCH3) and cell adhesion (PXN) to be differentially methylated in preoperative and postoperative saliva samples of OSCC patients compared to normal controls. Here, NTRK3 is linked to cancer.