Seven markers are involved in proliferation-sustaining signalling in ESCC, including epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2), phosphorylated mammalian target of rapamycin (p-mTOR), Cyclin D1, P16, P21, and P27 (Tables 1, 2). The gene discussed is CCND1; the disease is esophageal squamous cell carcinoma.