The two genes implicated in tuberous sclerosis, TSC1 and TSC2, with loci on chromosomes 9q34 (TSC1) and 16p13.3 (TSC2) respectively [2], [3], participate in the control of cell size via the insulin/p70 ribosomal S6 kinase 1 (S6K1) pathway [4]. This evidence concerns the gene TSC2 and tuberous sclerosis.