Mutations in the Vsx2 gene and deletion of the mR0-37 Vsx2 SE module leads to microphthalmia due to defects in retinal progenitor cell proliferation (Burmeister et al., 1996; Ferda Percin et al., 2000; Honnell et al., 2022; Livne-Bar et al., 2006; Truslove, 1962). Here, VSX2 is linked to microphthalmia.