EPO signaling in neural cells. In neural cells, EPO binds to the EPO-R dimmer and stimulates JAK2 kinase activity resulting in phosphorylation (P) of JAK2 and EPO-R. Activated JAK2 initiates signal transduction through several adaptor proteins such as Src homology containing protein (SHC), growth factor receptor-binding protein 2 (GRB2), son of sevenless protein-1 (SOS-1), and phosphoinositol 3-kinase (PI3-K). The downstream signaling messengers include the G protein (RAS), serine/threonine-specific kinase (RAF1), p38 mitogen-activated protein kinase (MAPK), extracellular response– stimulated kinase (ERK1/2), human oncogene (C-Fos), membrane phospholipids (phosphoinositol 3,4,5-phosphate, PIP3), protein kinase B (AKT), apoptosis inducer (BAD), anti-apoptotic protein (Bcl-xL), and the caspases. Additional signaling pathways contain signal transducer and activator of transcription 5 (STAT5) and Nuclear factor kappa B (NF-κB). All of these pathways have been found to affect the gene transcription in neural cells survive related to EPO.