Figure 2. Doxycycline and RS1 concentration in the retina. A: Doxycycline concentration in retinal lysates after topical administration of either 5 mg/ml or 10 mg/ml doxycycline. B: Quantification of the amount of RS1 protein in retinal lysates after a single injection of RS1-expressing constitutive mesenchymal stem cells (MSCs) or inducible MSCs at three post-injection time points. All data are presented as mean ± standard error of the mean (SEM; n = 3).