In detail, we investigated whether (i) the ascorbate-induced generation of ROS was serum-dependent, (ii) the susceptibility to ascorbate-induced cytotoxicity in the 60 cancer cell lines of the NCI60 panel was merely influenced by exogenous O2 availability and/or by HIF1α and (iii) correlated with the endogenous GLUT-1 expression. This evidence concerns the gene SLC2A1 and cancer.