HSP90B1 and Cowden disease: The intestinal mucosa of CD patients showed an upregulation of the co-chaperone DNAJC3 (Fig 5A), the HSPA5 gene that encodes GRP78/BiP protein (Fig 5B), the HSP90B1 gene that encodes GRP94 (Fig 5C) and the CALR gene that encodes the chaperone calreticulin (Fig 5D), corroborating our previous results of ER stress activation in the intestinal mucosa of CD patients.