Recent discoveries reveal that the vast majority of the genome is transcribed to generate tens of thousands of long noncoding RNAs (lncRNAs). However, deciphering the molecular function of lncRNAs is challenging. Unlike mRNAs, there is currently no simple way to predict lncRNA activity based on sequence. Initial studies of individual lncRNAs have shown important roles in epigenetic regulation and powerful biological functions, but almost nothing is known about lncRNA function in neural specification or human disease pathogenesis. Based on the overall hypothesis that lncRNAs play important roles in normal brain function and disease conditions, I aim to systematically decipher the roles of lncRNAs in neural differentiation and breast cancer. This will provide comprehensive references, new mechanisms and novel therapeutic targets for neurodevelopmental disorders and breast cancer.