ATG4D and nasopharyngeal carcinoma: The prevalence of positive expression for autophagy-related proteins among NPC patients was as follows: ATG1 (91.43%); ATG2A (0%); ATG2B (65.71%); ATG3 (85.71%); ATG4A (94.29%); ATG4B (57.14%); ATG4C (62.86%); ATG4D (5.71%); and ATG5 (100%).