CASC15 and non-small cell lung carcinoma: Mechanistic study revealed that two adjacent HREs located in the CASC15 promoter are indispensable for hypoxia-induced CASC15 upregulation (Fig. 4).Moreover, we also found that the expression levels of CASC15 in NSCLC cells were significantly higher than those in normal human bronchial epithelial cell line BEAS-2B under normoxic conditions (Fig. 1c).