Similarly, other reported downstream target genes like CDK4, CCND1, CDH1 and BCL2 did not respond to up- or downregulation of CASC9 in HNSCC cells and only BCL2 and E-Cadherin (CDH1) expression correlated moderately with CASC9 expression across our cell line panel, indicating that they may be rather coregulated by common underlying mechanisms. This evidence concerns the gene CDK4 and head and neck squamous cell carcinoma.