['Accumulating evidence suggests that dysregulated snoRNA may play a role in the development of malignancy. In the present study, we investigated the role of SNORD78 in the tumorigenesis of non-small cell lung cancer (NSCLC).', 'We determined the expression level of SNORD78 in NSCLC tissues with quantitative real-time PCR and then studied its clinical significance. We explored the biological significance of SNORD78 with gain-and-loss-of-function analyses both in vitro and in vivo.', 'A great upregulation of SNORD78 was observed in cancer tissues compared to their adjacent normal tissues. Meanwhile, patients with high SNORD78 expression have significantly poorer prognosis than those with low expression. Inhibition of SNORD78 suppressed the proliferation of NSCLC cells via inducing G0/G1 cell cycle arrest and apoptosis while SNORD78 overexpression promoted the cell proliferation. SNORD78 promoted invasion of NSCLC cells via inducing epithelial-mesenchymal-transition (EMT). SNORD78 was also obviously upregulated in cancer stem-like cells and is required for the self-renewal of NSCLC. The oncogenic activity of SNORD78 was also confirmed with in vivo data.'] Does small nucleolar RNA 78 promote the tumorigenesis in non-small cell lung cancer?