PIWIL2 and esophageal squamous cell carcinoma: The result revealed that PIWIL2 overexpression significantly increased the number of AVs from 5.3 ± 2.7 to 7.7 ± 2.6 per cellular cross section (p = 0.003, Fig. 2c), suggesting that PIWIL2 can promote autophagy in ESCC cells.