POSTN and lupus nephritis: In a study on a small cohort of patients with immunoglobulin A nephropathy and lupus nephritis, Wantanasiri et al. (103) reported a worse kidney function and higher urinary POSTN excretion levels compared with these in healthy controls; additionally, in patients who were responsive to treatment, there was a significant decrease in urinary POSTN levels at 6 months of follow-up.