Figure 4. Lack of LIF alters gene expression after light exposure. Relative levels of mRNAs (as indicated) were analyzed by real-time PCR in retinas of Lif^+/– and Lif^–/– mice before (controls) or at 12 h after exposure to 15,000 lx of white light for 2 h. RNA levels were expressed relative to levels in Lif^+/– controls, which were set to 1. β-actin served as reference gene for the relative quantification. Bars show mean values±SD (n=3).