CCND1 and esophageal squamous cell carcinoma: Especially in ESCC, oncogenes, such as SMYD2 (1q32.3-q41), EGFR (7p12), MYC (8q24.21), CCND1 (11q13), cIAP1 (11q22) and ERBB2 (17q21.1), have already been identified as major amplification targets associated with development, progression and metastasis of aggressive disease (Lu et al, 1988; Imoto et al, 2001; Jain et al, 2007; Komatsu et al, 2009; Sato-Kuwabara et al, 2009).