MAGEA4 and head and neck squamous cell carcinoma: MAGE-A4 is expressed in solid cancers, including synovial sarcoma (SS), myxoid/round cell liposarcoma (MRCLS), non-small-cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and ovarian, urothelial, melanoma and gastroesophageal cancers1–5.