Unlike previous reviews-which focused primarily on individual PPAR subtypes or isolated pathological processes-this review adopts a unique "cell-type-specific perspective." It systematically elucidates the distinct roles of all three PPAR isotypes (α, γ, and β/δ) across key renal cell types (podocytes, mesangial cells, tubular cells) in DKD. This evidence concerns the gene PPARA and diabetic kidney disease.