TLR5 and lupus nephritis: We have observed that the GFP-labeled MSCs migrated to the tubular region and proliferated locally within the kidneys of B6.Sle1.Sle3 mice with lupus nephritis but not in B6 mice (data not shown), indicating that MSCs have the propensity to migrate to the site of tissue injury and potentially ameliorate injury by producing renotrophic factors [46]–[48].