MTOR and systemic lupus erythematosus: Although the mammalian target of rapamycin (mTOR), a sensor of mitochondrial homeostasis in T cells, is activated in SLE patients, blockade of mTOR with rapamycin, for example, incompletely reverses mitochondrial hyperpolarization and fails to correct accumulation of mitochondria, suggesting that mitochondrial dysfunction occurs upstream of mTOR activation in SLE (57).