Consistent with the initial findings, biopsies from patients with hypertensive nephropathy, various glomerulopathies and CAN demonstrated intense periostin expression predominantly in the region presenting tubular atrophy, interstitial fibrosis, tubular epithelial cells, periglomerular fibrosis and glomerular mesangium [10–12]. The gene discussed is POSTN; the disease is Crouzon syndrome-acanthosis nigricans syndrome.