HIF1A and small cell lung carcinoma: Hypoxia up-regulated the transcription of glycolysis genes in SCLC cells and knockdown of HIF1A by either siHIF1A or shHIF1A resulted in abrogation of hypoxia-induced expression of glycolysis-related genes, such as GLUT3, GLUT1, HK2, ALDOA, PDK1, LDHA and SLC16A3 (Figure 3A and Supplementary Figure 4).