The upregulation of LUM and other ECM proteins such as NID2 and COL4A1 in microphthalmia patient OVs in contrast to the loss of Lumican in animal models of increased axial length may be indicative of an inversely proportional relationship between the ECM and axial length (Eiraku et al., 2012). Here, COL4A1 is linked to microphthalmia.