For instance, erythropoietin (EPO) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are able to promote erythropoiesis via the activation of the Janus kinase (Jak)2/signal transducer and activator of transcription (STAT)5 signaling pathway [12,13,14,15], while interferon (IFN) γ can lead to anemia partially through induction of the IFN regulatory factor (IRF)1/purine-rich nucleic acid binding protein.1 (PU.1) signaling pathway [16]. Here, EPO is linked to anemia (phenotype).