ATG4B and nasopharyngeal carcinoma: In EBV-negative NPC patients, the positivity rates were: 80% for ATG1 (4 patients); 0% for ATG2A; 40% for ATG2B (2 patients); 40% for ATG3 (2 patients); 80% for ATG4A (4 patients); 20% for ATG4B (1 patient); and 0% for both ATG4C and ATG4D, while ATG5 was positive in 100% (5 patients).