Mutation within the TSC1 gene is responsible for Tuberous sclerosis (TSC), an autosomal dominant genetic disorder associated with the development of benign tumors (hamartomas), a condition also induced by mutation of the Tumour sclerosis complex 2 (TSC2) gene. Many proteins have been shown to play a role in the regulation of the serine/threonine kinase known as target of rapamycin (TOR), a central component in a complex signaling pathway which controls cell proliferation and cell cycle progression. Negative regulation of TOR activity occurs following the over-expression of the TSC1 and TSC2 gene products, hamartin and tuberin. These act by suppressing the phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 (4EBP1) and ribosomal protein S6 kinase (S6K), downstream targets of TOR involved in mRNA translation. Furthermore the TOR activator protein Rheb has been identified as a target of TSC1-TSC2 complexes.Synonyms: KIAA0243, TSC, Tuberous sclerosis 1 protein