ATG4B and nasopharyngeal carcinoma: Furthermore, elevated expression levels of both ATG4B and ATG4D were more frequently observed in the No Distant Metastasis (M0) category compared to the Distant Metastasis (M1) category across the entire cohort of NPC patients (P = 0.019 for both ATG4B and ATG4D) and within the EBV-positive subgroup (P = 0.014 for both ATG4B and ATG4D).