Since Usp11 encodes a DUB, we reasoned that Usp11 deficiency may lead to increased ubiquitination and destabilization of a protein that functions in neuronal differentiation and migration.To define the molecular mechanism of Usp11 deficiency on cortical development, we performed a label-free quantitative liquid chromatography-tandem Mass Spectrometry (LC-MS/MS) analysis to detect the protein expression profiles in E17.5 WT and Usp11 KO cortices in four biological repeats.