SMAD4 and head and neck squamous cell carcinoma: Remarkably, most of the genes overtargeted by DA miRNAs and playing central roles in our HNSCC miRNA-mRNA interaction networks (such as DICER, PTEN, CDKN2A, NOTCH, MDM2, CCND1, HRAS, and SMAD4 among others) (Figures 4 & 5) were previously reported within a group of genes altered in HNSCC (reviewed in [9]).