Forced expression of Hoxb13 promotes differentiation of NRP152 cells. A, NRP-152 cells infected with pHR′-CMV-EGFP control vector immunostained with CK8 show lack of luminal cell differentiation. B, Cell culture infected with pHR′-CMV-Hoxb13 showed robust CK8 staining in many cells after 72 h suggesting differentiation to a luminal phenotype. C and D, Colocalization of Hoxb13 and CK8 in the same cells. C, All Hoxb13 (green)-positive cells immunostained for CK8 (red) in the cytoplasm. D, Merged image of DAPI (blue)-stained cells reveals that Hoxb13-negative nuclei (arrowhead) do not express CK8, whereas Hoxb13 positive (arrow, green) cells express CK8 (red) (scale bar, 50 μm).