Reelin is a large extracellular protein of 430 kDa, which plays critical roles in layer formation of neurons in the cerebral cortex and cerebellum. Reelin deficient mouse disrupts neuronal migration in brain. ApoER2 (Apolipoprotein E receptor2) and VLDLR (very low density lipoprotein receptor) are LDL receptor gene family member, which binds to Reelin through the ligand-binding type A (LA) repeats. Binding of Reelin to ApoER2 and VLDLR induces the adaptor protein Dab1 phosphorylation in neurons. ApoER2 has two splice variants, LA1237 and LA12378, that differs in the number of LA repeats and their expression pattern is different. ApoER2-LA12378 is involved in the regulation of Purkinje cell migration and neuronal circuit formation of cerebellum.