ATG4C and nasopharyngeal carcinoma: In EBV-negative NPC patients, the positivity rates were as follows: ATG1 (80%); ATG2A (0%); ATG2B (40%); ATG3 (40%); ATG4A (80%); ATG4B (20%); ATG4C (0%); ATG4D (0%); and ATG5 (100%).