The methylation detection method of p16INK4a in HNSCC and control included 16 studies used methylation-specific polymerase chain reaction (MSP), three studies used real-time quantitative MSP (QMSP), one study used PCR-based methylation-sensitive restriction analysis (MSRA), and one study used pyrosequencing (Pyro). The gene discussed is CDKN2A; the disease is head and neck squamous cell carcinoma.