The homeodomain transcription factor Chx10 is one of the earliest markers of the developing retina. It is required for retinal progenitor cell proliferation as well as formation of bipolar cells, a type of retinal interneuron. CHX10 lentivirus (TET-inducible, Puro) expresses human CHX10 under the control of the Tet responsive promoter, with puromycin as a selection marker.