CRBN, a member of the Lon protease protein family, plays a role in brain development (1). It is a component of the DCX (DDB1-CUL4-X-box) E3 protein ligase complex, a complex that mediates the ubiquitination and subsequent proteasomal degradation of target proteins and is required for limb outgrowth and expression of the fibroblast growth factor FGF8 (2). CRBN is thought to regulate the assembly and neuronal surface expression of large-conductance calcium-activated potassium channels in brain regions involved in memory and learning via its interaction with KCNT1. It is widely expressed and highly expressed in brain (3,4).