PVR and head and neck squamous cell carcinoma: We associated genes that are activated or have gain-of-function in other cancers with those found in HNSCC, e.g., HOXB4, PVR, RHOA, ADRBK1 and CCR4. Pathways that are common to multiple cancers can be identified by incorporating these types of oncogenes from multiple studies (Additional File 1, Table S6 and Table S7).