Because the pathway analyses identified a prominent role for TGFβ in ROP-Os/+−dependent FSGS pathogenesis, we there fore compared TGFβ proteinbetween ROP-Os/+ and C57-Os/+ kidneys using Western blot analysis, and found no significant difference between the two strains (Figure 3). Here, TGFB1 is linked to retinopathy of prematurity.