Angiotensin converting enzyme (ACE) tended to be upregulated in CHF vs. NF (0.94 ± 0.35 vs. 0.50 ± 0.13 AU, P = 0.099), which reached statistical significance only when comparing CHF patients with lower vs. higher than median LVEF at baseline (P = 0.028) indicating a more pronounced ACE upregulation in more severely impaired left ventricles. This evidence concerns the gene ACE and congestive heart failure.