EPO and hydrops fetalis: It is also known from the proven efficacy of gliflozines that by stimulating hypoxia-inducible factors, HIF-1 induces expression of hemoxygenase 1, a tissue-protective gene [70], and HIF-2 activation enhances erythropoietin expression [71] and release from renal interstitial cells, which, together with the diuretic effect of the drugs, may contribute to the clinically observed modest increase in hematocrit and hemoglobin in HF patients [72].