CDNF and Parkinson disease: Overexpression of CDNF renders astrocytes less sensitive to ER stress-induced cell damage in vitro and reduces the expression and secretion of pro-inflammatory cytokines both in cell culture (Cheng et al., 2013), in the 6-hydroxydopamine (6-OHDA) rat model of PD (Nadella et al., 2014) and in degenerating retina (Neves et al., 2016).