In addition, a recent study revealed that bone morphogenetic protein 9 (BMP9), despite inhibiting lymphatic vessel maturation and valve formation, has no effect on the Schlemm’s canal or intraocular microscopic lymphatic vessels and has no effect on intraocular pressure (IOP), rendering it unsuitable for use as a novel therapeutic target for glaucoma (Subileau et al., 2020). Here, GDF2 is linked to glaucoma.