APOL1 is not expressed in proximal tubules and is not filtered

The kidney expression pattern of APOL1 was examined using both protein and mRNAin situmethods onAPOL1bacterial artificial chromosome transgenic mice, with and without proteinuria. APOL1 was detected in podocytes and endothelial cells of the kidney, but was not expressed in tubular epithelia, nor was plasma APOL1 protein filtered and reabsorbed by the proximal tubule. APOL1 expression in podocytes and endothelia should remain the focus for mechanistic studies of APOL1-mediated pathogenesis.