KLF4 and lung neuroendocrine neoplasm: Guo Zhang et al. demonstrated through CHIP experiments that KLF4 binds to the promoter of surviving in esophageal squamous cell carcinoma and inhibits its activity, which can induce apoptosis of cancer cells (Zhang et al., 2009), KLF4 expression is also altered in neuroendocrine lung tumors, and its downregulation may be associated with invasiveness (Naranjo Gómez et al., 2014).