IGF1 and retinal degeneration: Liu et al. have reported that a Sca1+ BMSC subpopulation from aged mice exhibited lower paracrine support for retinas than a Sca1+ BMSC subpopulation from young mice [60], and injecting young Sca-1+ BMSCs into 18-month-old mice through the tail vein can increase brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), FGF2, and insulin-like growth factor 1 (IGF-1) expression, downregulation of the apoptotic protein Bax with upregulation of the antiapoptotic protein Bcl2 to attenuate aging-related retinal degeneration ultimately [60].