One reason why nipbl-morphant zebrafish may provide such a good model for CdLS is that the early insensitivity of nipblb to MO-mediated knockdown (Figures 2, S3) may fortuitously make the total decrease in Nipbl function in nipbla/b-morphant embryos approximate what occurs in human and murine NIPBL-haploinsufficiency [21],[23]. This evidence concerns the gene NIPBL and Cornelia de Lange syndrome.