In addition, PIWIL1 has been described to exhibit a poor prognostic value in soft-tissue sarcoma [45,46], esophageal squamous cell carcinoma [47], colorectal cancer [48,49,50], gliomas [51], human hepatocellular carcinoma [52,53], gastric cancer [54,55], lung cancer [56], gynecological cancers [57,58,59], renal cell carcinoma [60,61], and non-small cell lung cancer [62]. This evidence concerns the gene PIWIL1 and esophageal squamous cell carcinoma.