MAPK3 and Charcot-Marie-Tooth disease type 1A: Moreover, a disturbed balance of the phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (AKT) and the mitogen activated protein kinase (MAPK)-extracellular-signal-regulated kinase 1/2 (ERK1/2) signaling pathways (also known as the Ras-Raf-MEK-ERK1/2 pathway) seem to lead to Schwann cell differentiation and myelination deficits in young CMT1A rats [8].