IGFBP3 and Parkinson disease: Furthermore, the frequent co-occurrence of Lewy body pathology in both PD/AD dementia suggests shared pathogenic mechanisms, with the insulin signaling pathway potentially playing a role in PDD development, because insulin signaling molecules have been shown to exert neuroprotective and proliferative functions by enhancing cell survival, preventing apoptosis, and stimulating neuronal development in areas such as the hippocampus, low expression of IGFBP3 may have affected the development and survival of neurons (Yang et al., 2018).