In addition, the mRNA expression levels of angiotensin converting enzyme 1 (ACE1) in the ROP+ACEi group (3.00-fold ± 0.81) were significantly higher than in the ROP-Ctrl group (0.63-fold ± 0.17) (P = 0.0037) and in the SHAM group (1.00-fold ± 0.22) (P = 0.0275). Here, ACE is linked to retinopathy of prematurity.