Tuberous Sclerosis Complex 2 (TSC2), also known as Tuberin, is a protein that in humans is encoded by the TSC2 gene. Mutations in this gene lead to tuberous sclerosis. Its gene product is believed to be a tumor suppressor and is able to stimulate specific GTPases. The protein associates with hamartin in a cytosolic complex, possibly acting as a chaperone for hamartin. Alternative splicing results in multiple transcript variants encoding different isoforms of the protein. Together with tuberous sclerosis, mutations in TSC2 can cause Lymphangioleiomyomatosis. Because Tuberin regulates cell size, along with the protein Hamartin coded by the gene TSC1, mutations to these genes may prevent the control of cell growth in the lungs of individuals.