TLR2 and diabetic kidney disease: In 2013, we found that MSCs can improve glomerular fibrosis in DKD, improve renal function by inhibiting oxidative stress and macrophage infiltration [44]; Later, we found that MSCs can also inhibit the innate immune signaling pathways mediated by TLR2 and TLR4 in podocytes and DKD, reduce the expression of inflammatory factors, and significantly reduce physiological indicators including body weight, blood glucose, urinary albumin [20].