Another study found that the TREM-1/TREM-2 ratio was decreased in patients with CKD, and notably, this ratio was significantly lower in patients with moderate-to-severe fibrosis than in those with non-mild renal fibrosis, suggesting that the urinary TREM-1/TREM-2 ratio could serve as a potential biomarker for diagnosing renal fibrosis [142]. Here, TREM2 is linked to fibrosis.