CCND1 and esophageal squamous cell carcinoma: Among identified alterations, amplification of 11q13 is the most frequent gain observed, harboring FGF19, SHANK2 and CCND1. We further found that CCND1 expression was frequently upregulated in primary ESCC tumors, and DNA amplification contributes to its overexpression, which is correlated with lymph node metastasis of primary ESCC tumors.