KL and head and neck squamous cell carcinoma: The abnormal autophagy in tumors may be associated with Klotho underexpression, which has been documented in hepatocellular carcinoma (Shu et al., 2013), head and neck squamous cell carcinoma (HNSCC) (Zhu et al., 2019), gastric cancer (Xie et al., 2013b), as well as lung cancer (Chen et al., 2016).