APEX1 and neoplasm: Genes within glycolysis and TCA cycle demonstrated similar reduction in expression with both Ref-1 siRNA and APX2009 treatment, with the exception of the SDHA gene (Supplemental Fig. S1H-M), As 3D spheroid cultures of PDAC cells mimic in vivo tumor hypoxic regions, further evaluation of these genes was done using Pa03C spheroids.