Interestingly, HtrA1 is shown to be upregulated in the peripheral blood of retinopathy of prematurity (ROP) patients, a condition characterized by aberrant retinal vascular maturation and oxygen-induced retinopathy murine model of ROP demonstrated that mice overexpressing HtrA1 demonstrated greater ROP disease activity, supporting the pro-angiogenic function of HtrA1 [40]. Here, HTRA1 is linked to retinopathy of prematurity.