In this context, we could also not detect compensatory upregulation of PHD2 or PHD3 after HIF‐2 stabilization under anaemia or PHD inhibition, neither in medullary fibroblasts as a possible counterregulation to prevent EPO induction, nor in EPO+ and EPO− fibroblasts in the cortex (Fig. 9). The gene discussed is EPO; the disease is anemia (phenotype).