Since others have reported that IGFBP-3 can be antiapoptotic to the retina in the oxygen-induced retinopathy model [25,29], these findings suggest that the increased cleaved caspase 3 observed in the β1-adrenergic receptor KO mice may be due to reduced levels of IGFBP-3 in the retinal endothelial cells, resulting in increased apoptosis through IGF-1 receptor-independent effects. Here, IGFBP3 is linked to retinal disorder.