PRL and type 1 diabetes mellitus: In the present study, we were able not only to validate that HSPB1 is a key mediator of the cytoprotective effects mediated by prolactin in type 1 diabetes context [9,10], but also to demonstrate that HSPB1 upregulation, independently of PRL treatment, is sufficient to protect beta-cells and murine islets against ER stress-induced cell death.