Inhibitor of the serine/threonine-protein kinase PAK4. Acts by binding PAK4 in a substrate-like manner, inhibiting the protein kinase activity. Interacts with PAK4 (PubMed:17314132). Mainly nuclear. Relocalizes to the cytoplasm following interaction with PAK4. Expressed in tissues of the developing head during neurulation. Expressed in the cephalic mesenchyme, heart and paraxial mesoderm prior to 8.5 dpc. Expression is then observed in the migratory neural crest cells and their derivatives. As development progresses, expression is also observed in the limb buds and perichondrial tissue. Contains 2 Inka boxes (also named iBox or inca box). The Inka boxes bind and inhibit PAK4 by binding a substrate-like manner. No visible phenotype in most cases: most mice are viable and fertile. A low percentage of mice show exencephaly. Expression of Inka1 is not regulated by AP-2-alpha/Tfap2a, as it is the case for orthologous protein in zebrafish and Xenopus. Belongs to the INKA family.