Molecular studies. RT-PCR data were obtained as described using EPAS1/HIF-2α null bone marrow cDNA and graphed relative to the wild-type gene of interest signal (set at one). The data are presented for a panel of genes involved in (A) VEGF production (VEGF A, B, C, D)and VEGF signaling (Flt-1, Flk-1, Nrpln), or (B) endothelial cell signaling (FN, uPAR, uPA, VCAM, VECAD), as well as the internal control (β-actin). Differences in FN, uPAR, and VCAM levels were all significant for P < .05 as assessed by 2-tailed t test. No other significant differences between genotypes were noted for the other gene products. Error bars indicate SEM.