PIWIL1 and esophageal cancer: For instance, in esophageal cancer (He et al., 2009), colon cancer (Wang H.L. et al., 2015; Sun et al., 2017), cervical cancer (Liu et al., 2010a, 2014), renal cell carcinoma (Stöhr et al., 2019), and endometrial cancer (Chen et al., 2015a), PIWIL1 levels were significantly increased in late-stage tumors than in early stage tumors.