FSTL1 and diabetic kidney disease: Bioinformatic analyses have specified potential immune-associated biomarkers in tubulointerstitial injury in DKD, including anterior gradient 2 (AGR2), C-C motif chemokine receptor 2 (CCR2), CCAAT enhancer binding protein delta (CEBPD), cytokine-inducible SH2-containing (CISH), C-X3-C motif chemokine receptor 1 (CX3CR1), human β-defensin-1 (DEFB1), and follistatin-like protein 1 (FSTL1), which correlate with renal function markers [23].