Moreover, across our panel of 21 HNSCC cell lines no correlations were observed between CASC9 and CDK4 or Cyclin D1 and only weak correlations for E-Cadherin (Pearson r = 0.48) and BCL2 (Pearson r = 0.50) (Additional file 2: Figure S3A-D). This evidence concerns the gene CDK4 and head and neck squamous cell carcinoma.