An intracellular signaling and tumor suppressor protein that forms a complex with TUBEROUS SCLEROSIS COMPLEX 1 PROTEIN (TSC1) and other signaling factors to negatively regulate MTORC1 and affect cell growth and proliferation. It can also function as GTPASE-ACTIVATING PROTEIN (GAP) for RHEB GTPASE to activate mTORC1 independent of its role in the complex. Structurally, it interacts with TSC1 through its N-terminus, which also contains a leucine zipper and coiled-coil region. It also has multiple phosphorylation sites for different cell signaling kinases, a central coiled-coil region, a C-terminal GAP domain and CALMODULIN binding domain. Mutations in the TSC2 gene are associated with TUBEROUS SCLEROSIS.