Low phz concentrations did not increase the expression of hypoxia markers in eng−/− and even reduced it if considering only egln3 (mean fold increase compared to that in non-treated siblings for eng−/− versus eng−/− treated with phz at 0.625 and 1.25 μg/ml: epoa, 6.1 versus 5.9 and 5.7, respectively; egln3, 6.0 versus 1.9 and 2.6, respectively), suggesting that heart failure would further worsen oxygenation. The gene discussed is EGLN3; the disease is heart failure.