E). STAT3 was phosphorylated in retinal ECs after LIF treatment. 50 ng of our in-house LIF with low-endotoxin levels was injected. Phospho-Stat3 was examined on cryosection of retina after 2 hour by IHC. Magnification in the dashed box is shown in the lower panel. n = 5. Scale bar = 100 µm. 