Injection of superparamagnetic iron oxide superparamagnetic Iiron oxide into the anterior chamber of mice to block aqueous humour outflow and simulate angle-closure glaucoma (20, 30) increased the IOP in both WT and PD-L1/PD-L2 dKO mice (Figure 1A). The gene discussed is PDCD1LG2; the disease is angle-closure glaucoma.