OPN1LW and retinopathy of prematurity: However, the protein expression levels of NEP1 in the ROP+ACEi group (0.42-fold ± 0.18) were significantly lower than in the SHAM group (1.00-fold ± 0.38) (P = 0.0023), ROP-Ctrl group (0.75-fold ± 0.18) (P = 0.0489), and ROP+ARNi group (1.11-fold ± 0.25) (P = 0.0004), respectively (Figures 4D, E).