TAF1 and cask-related x-linked intellectual disability: To deplete taf1 gene expression in zebrafish embryos, a transient in vivo splice-blocking morpholino approach was taken (O'Rawe et al., 2015); both approaches reduced the area of the optic tectum (midbrain) indicating microencephaly, comparable to that in human patients with XLID (Gudmundsson et al., 2019; O'Rawe et al., 2015).