CYP1B1 and coloboma: Similar to the effects observed with the zebrafish gene, the overexpression of human CYP1B1 caused large colobomas in 71.8 ± 17.9% of embryos (P = 0.0003, Supplementary Table S5), reflecting the defective closure of the ocular fissure (Figs. 8B, 8B') compared to controls (Figs. 8A, 8A').