While anaemia with haematocrit levels of about 25% was apparently not a sufficiently strong hypoxic stimulus to stabilize HIF‐2α in deeper medullary fibroblasts, a clear HIF‐2α stabilization in interstitial fibroblasts of all renal zones, including the papilla, could be detected after serial administration of PHDi (Fig. 2). Here, EPAS1 is linked to anemia (phenotype).