The CIT gene encodes a kinase that catalyzes the phosphorylation of serine and threonine residues in proteins. The CIT protein localizes to the cleavage furrow and midbody of mitotic cells where it is needed for the positive regulation of cell cytokinesis. It is also required for the regulation of actin polymerization and depolymerization. Multiple isoforms of the CIT protein exist due to alternative splicing. The gene is found to be overexpressed in the frontal cortex and basal ganglia of the brain.
By playing a role in the generation of neurons and the neuron apoptotic process, CIT is involved in the development of the central nervous system. The gene is hence associated with Microcephaly 17, Primary, Autosomal Recessive (MCPH17), a congenital neurologic disorder characterized by reduced head circumference, facial dysmorphia, delayed psychomotor development, intellectual disability, axial hypotonia, spasticity and a failure to thrive. Homozygous mutations in the CIT gene are associated with MCPH17.