CCND1 and head and neck squamous cell carcinoma: In support for this model, it has been shown previously [38] that upregulation of cyclin D1 (CCND1) expression was detected in oral hyperplasia/premalignant lesions and CCND1 gene locus (11q13) amplification was found in early dysplasia, carcinoma in situ and also metastatic HNSCC.