The underlying causes of autism spectrum disorders remain confusing and controversial; however, emerging research has linked some autism cases to various genetic factors. Recently, mutations in the protein PTEN have been identified in autistic patients with macrocephaly. The PTEN protein is mainly thought to be involved in suppressing cancer, but may in fact play an important role in autism. This research has two main goals: investigating the role of PTEN dysfunction in autism and developing a protein drug that may have therapeutic value for autistic patients. To investigate the role of PTEN in autism, the fellow aims to create several variant PTEN proteins, each with a mutation that is linked to autism, and compare them to normal PTEN protein. By characterizing the differences between the normal and mutant proteins, the study should yield a better understanding of the effect these mutant proteins may have on autistic patients. To develop a protein drug, the fellow plans to engineer the PTEN protein so that it possesses the ability to travel across cellular membranes. By endowing normal PTEN with the ability to enter a cell, it can take the place of mutant PTEN and potentially alleviate autistic symptoms.