RBBP4 and microcephaly: In comparison to uninjected rbbp4on/Δ4 larvae which appear morphologically normal (Figure 6B), 5 dpf rbbp4on/Δ4 Cre mRNA-injected larvae display the rbbp4 microcephaly and microphthalmia loss-of-function phenotype, and induction of RFP expression (Figure 6C).