CLN3 and glycogen storage disease VI: More recently, a study aimed to understand the role of CLN3 in retinal pigment epithelium (RPE) structure and function by generating iPSC-RPE cells from fibroblasts of CLN3 disease patients has implicated the contribution of the CLN3 gene in RPE dysfunction and photoreceptor outer segment (POS) phagocytosis in CLN3 disease [107].