The nuclear receptor subfamily 2 group F member 1 (NR2F1), a key regulator of tumor dormancy, is epigenetically up-regulated by promoter hypermethylation in experimental head and neck squamous cell carcinoma (HNSCC) dormancy models and DTCs from prostate cancer patients carrying long-term dormant disease [41]. The gene discussed is NR2F1; the disease is head and neck squamous cell carcinoma.