PCTK3 may play a role in signal transduction cascades in terminally differentiated cells. Function: May play a role in signal transduction cascades in terminally differentiated cells. Tissue Location: Isoform 3 expression is limited to several subcortical nuclei of the basal gangli and the spinal cord Isoform 2 is widely expressed.Synonyms: Cell division protein kinase 18, Cyclin-dependent kinase 18, PCTAIRE 3, PCTAIRE-3, PCTAIRE-motif protein kinase 3, PCTAIRE3, Serine/threonine-protein kinase PCTAIRE-3