CASC15 and gastric cancer: The overexpression of the lncRNA CASC15 has been reported in several studies and shown to play an oncogenic role by regulating the epithelial-mesenchymal transition (EMT) and enhancing gastric cancer cell proliferation; moreover, CASC15 is associated with poor patient prognosis [40] and regulates the progression of tongue squamous cell carcinoma by competing with miR-33a-5p [41].