Controls cell proliferation in a tissue-specific manner and is involved in morphogenesis. During embryonic development, exerts a role in the expansion of muscle progenitors. May play a role in the proper localization of asymmetric organs such as the heart and stomach. Isoform Ptx2c is involved in left-right asymmetry the developing embryo. Interacts with PITX2. In day-11 embryos, expressed in the periocular mesenchyme, maxillary and mandibular epithelia, umbilicus, Rathke pouch, vitelline vessels and limb mesenchyme. In adult tissues, expressed in pituitary gland, brain, kidney, eye, lung, testis and tongue. Expressed in the embryonic heart. Expressed in the left lateral plate mesoderm and symmetrically in the head mesoderm at 8.5 dpc. Isoform Ptx2c is expressed in the ventral outflow tract region (OFT), right ventricle (RV) and in the left atrium of the heart. Phosphorylation at Thr-90 impairs its association with the CCND1 mRNA-stabilizing complex thus shortening the half-life of CCND1. Mice embryos lacking isoform Ptx2c show left-right patterning defects and severe developmental abnormalities. Produced by alternative initiation at Met-35 of isoform Ptx2C. Belongs to the paired homeobox family. Bicoid subfamily. Extended N-terminus.