Knockdown of endogenous miR-181a expression in primary BECs results in increased Prox1 levels. Prox1 mRNA expression is increased in primary embryonic BECs after transfection with anti–miR-181a, compared with a negative control anti-miRNA that has no established targets; n = 6. *P < .001. Data are mean ± SEM and are representative of 2 independent experiments. P value was calculated using Student paired t test.