HIF1A and sarcoma: We have previously shown that the expression of HIF-1α and 25 other hypoxia-related genes in human sarcomas is highly upregulated compared to normal tissues,19 and hypoxia in human sarcomas is associated with a higher risk of recurrence and decreased overall survival.44, 45 HIF-1α upregulates the expression of VEGF-A in sarcomas,19 and circulating levels of VEGF-A are elevated on average tenfold in patients with sarcoma compared to controls.20 In our study, we confirmed upregulation of HIF-1α under hypoxic conditions in four different sarcoma cell lines.