Notably, indications with ≥5 evaluable patients and ≥50% prevalence of MAGE-A4 positivity were adenoid cystic carcinoma (n = 9/11; 82%), liposarcoma (n = 4/6; 67%), ovarian serous/high-grade carcinoma (n = 9/14; 64%), squamous NSCLC (n = 7/11; 64%), HNSCC (n = 3/5; 60%), and esophageal cancer (n = 7/13; 54%). Here, MAGEA4 is linked to head and neck squamous cell carcinoma.