['To investigate the neuroprotective and immunomodulatory effects of mesenchymal stem cells (MSCs) engineered to secrete CX3CL1 on the light-injured retinal structure and function.', 'Normal MSCs and CX3CL1-expressing MSCs (CX3CL1-MSCs) were transplanted into the subretinal space of light-injured rats. By ERG and TUNEL methods, their rescue effect of the host retina was compared with untreated light-injured and vehicle-injected rats. Activated microglia in the retina were stained by ED-1 antibody, and Western blot was performed to quantify cytokines secreted by the retina post-transplantation.', 'ERG analysis showed better function in CX3CL1-MSC-injected group than other groups at 21 days after transplantation (p\u2009<\u20090.05). CX3CL1-MSCs inhibited apoptosis of the retinal cells and microglial activation. Neurotrophic factors expression in host retina that received CX3CL1-MSCs was stronger than in the retina that received normal MSCs. Conversely, the expression of proinflammatory factors was downregulated.'] Does transplantation of CX3CL1-expressing mesenchymal stem cells provide neuroprotective and immunomodulatory effects in a rat model of retinal degeneration?