Importantly, this constitutive UPR depends on insulin signalling, and disturbance of the INSR/P85/XBP1-mediated constitutive UPR in podocytes, for example, in type 1 diabetes (insulin deficiency) or type 2 diabetes (insulin resistance), is mechanistically linked with glomerular disease. This evidence concerns the gene PIK3R2 and type 1 diabetes mellitus.