APEX1 and congenital secretory chloride diarrhea 1: Of notice, APE1/Ref-1 up-regulation in HCC differs according to CLD etiology as mRNA levels were significantly higher in those related to HCV (2.11 ± 0.66, p = 0.036) as compared to alcohol (1.16 ± 0.37); intermediate values were found for HBV infection (1.86 ± 0.54).