MTOR and systemic lupus erythematosus: Another interesting therapeutic effect of rapamycin is its ability to reverse the senescent phenotype of mesenchymal stem cells from MRL/lpr mice and SLE patients through inhibition of the mTOR signaling pathway [44], suggesting that cellular senescence of cells constituting the microenvironment of hematopoietic stem cells may play an important role in the pathogenesis of SLE.