AGRN and brain ischemia: It was described that agrin, an important glycoprotein for ensuring the stability, number, and grouping of acetylcholine receptors (AChR) in the postsynaptic membrane, is increased in the acute and subacute phase after cerebral ischemia (Carin‐Levy et al., 2006; Schebakov et al., 2016; Scherbakov & Doehner, 2011).