Similarly, Neurog2, another driver of IP genesis and Tbr2 expression (Ochiai et al., 2009), is rapidly downregulated in IPs by Cbfa2t2 (MTGR1), an IP-specific transcriptional coregulator that is first induced by Neurog2, then binds and inactivates Neurog2 (Aaker et al., 2009). The gene discussed is NEUROG2; the disease is incontinentia pigmenti.