HK2 and non-small cell lung carcinoma: The expressions of two key glycolytic enzymes hexokinase II (HK-II) and pyruvate dehydrogenase kinase 2 (PKM2) are mediated by transcription factors hypoxia-inducible factor 1 (HIF-1) and tumor suppressor gene p53, respectively, and dysregulation of these two transcription factors by cigarette smoke [34, 35] represents a possible explanation for the enhanced glycolysis in CSE-treated NSCLC cells.