SP1 and lung carcinoma: Whether HIF participates in the hypoxia-induced activation of ALOX signaling in ECs has yet to be thoroughly investigated; however, the ALOX5 promoter contains putative binding sites for both early growth response protein 1 (EGR1) and specificity protein 1 (SP1), which function with HIF as coregulators of erythropoietin receptor expression in lung cancer cells (Su et al., 2019).