Epigenetic and genetic modifications and signaling pathways leading to head and neck squamous cell carcinoma (HNSCC). Oncogenic factors, mutations, cancer stem cells, or immune invasion can lead to genetic and epigenetic changes or alterations in signaling pathways, such as EGFR, NOTCH, and JAK/STAT, that lead to dysregulated epigenetic enzymes, shifting the balance toward oncogenic transformation in HNSCC growth and metastasis.