TREM2 and diabetic kidney disease: Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) -high macrophages are a type of lipid-associated macrophage initially identified in immune cells within adipose tissue using single-cell sequencing, and their presence has also been confirmed in kidney biopsy samples from DKD patients, particularly in glomerular and tubulointerstitial regions.