Acts as a potent transcriptional repressor of MSX1. Interacts with CREBBP/CBP, NOTCH1/p300 and HDAC1. Appears to exist in two distinct complexes in the cell, one which includes CREBBP and NOTCH1 and the other which contains HDAC1. Restricted to the dorsal embryonic central nervous system. Belongs to the Msh homeobox family.