TGFB1 and primary congenital glaucoma: However, also the presence LTBP3 in this region is of interest, as this protein binds to TGFB1, TGFB2, and TGFB3, and is thus involved in the same signalling pathway as CDKN2B. LTBP3 is further of interest because of its homology to LTBP2, which has been implicated in primary congenital glaucoma [36], [37].