ACE and retinopathy of prematurity: Prior studies showed that the development of ROP may be influenced by variants in two genes encoding components of the RAAS: the angiotensin-converting enzyme gene (ACE) (Haider et al. 2002; Yildiz et al. 2010; Lei et al. 2018; Poggi et al. 2015; Spiegler et al. 2010) and the angiotensin II receptor type 1 gene (AGTR1) (Poggi et al. 2015; Spiegler et al. 2010; Rathi et al. 2017; Mohamed et al. 2009).