ANGPTL4 and systemic lupus erythematosus: Vanarsa et al. (2020) employed a novel quantitative planar protein microarray to screen 1,000 proteins in the urine of SLE patients and reported that ANGPTL4 levels were significantly elevated in the urine of patients with active renal SLE compared with healthy controls and were markedly higher than those in patients with active nonrenal SLE.