PKNOX2 belongs to the three amino acid loop extension (TALE) superclass of homeodomain-containing proteins and encodes a polypeptide of 462 residues. Studies showed PKNOX2 might be involved in the regulation of limb zeugopod and deltoid crest development. PKNOX2 lentivirus (TET-inducible, Puro) expresses mouse PKNOX2 under the control of the Tet responsive promoter, with puromycin as a selection marker.