To further assess the MAPK activation, we performed immunoblotting analysis of MAPK phosphorylation in TSC2-deficient patient-derived cells, Tsc2-deficient rat uterine-leiomyoma-derived cells, Tsc2−/− mouse embryonic fibroblast (MEFs), and Tsc1−/− MEFs, and their TSC2- or TSC1-reexpressing counterparts cultured in nutrient-rich medium containing 10% FBS or nutrient-deprived FBS-free medium, repersenting two basal levels of MAPK phosphorylation. The gene discussed is TSC1; the disease is leiomyoma.