As shown in Figure 2B, and similarly to TGF-β2, the aqueous humor level of SIPA1L1 was 76.6 ± 1.5 ng/mL in the non-POAG eyes (n = 10) and significantly higher in the POAG eyes (96.8 ± 7.2 ng/mL, n = 8, P = 0.0075). Here, SIPA1L1 is linked to open-angle glaucoma.