CHAT and retinal disorder: In addition, the expression of cholinergic neuron markers (CHAT and MEGF11) in SACs showed the same trend as the cellular communication of SACs with corresponding alternated ligand signaling, such as VEGF, FGF, and PDGF (Fig. 4H and I), further indicating the critical role of SACs in the source of acetylcholine in the retina and might jointly regulate retinal development and angiogenesis in blood vessel-associated cells in retinal disorders [62,69].