Hoxd11

iMSCs and UMSCs at passage 5, iPSCs at passage 15 were fixed in 4% paraformaldehyde solution for 20 min and permeabilized with 0.5% Triton X-100 in PBS for 15 min at room temperature. After 120 min blocking with 3% BSA (SIGMA), cells were incubated with primary antibody overnight at 4 °C. On the next day, cells were washed, and stained with secondary antibodies (1:300, goat anti-rabbit IgG-Cy3; or 1:300, goat anti-mouse IgG-FITC) for 60 min at room temperature and then washed three times with phosphate-buffered saline (PBS). For human umbilical cord tissue, paraffin sections were cleared of paraffin, hydrated, and were blocked in 1% BSA for 2 h at room temperature and then incubated with primary antibodies at 4 °C in a humidifying box overnight, followed by incubation with secondary antibodies for 1 h in the dark at room temperature. The primary antibodies for respective cells include MKI67 (1:300, Abcam), OCT4 (1:200, Abcam), SOX2 (1:200, Abcam), NAONG (1:200, Abcam), SSEA4 (1:200, Abcam), TRA160 (1: 200, Abcam), THY1 (1:200, Abcam), IL6 (1:100, Abcam), HOXD11 (1:100, Abcam), NESTIN (1:100, Abcam). DAPI (4′,6-diamidino-2-phenylindole) (1:500) was used as counter-staining for nuclei. The images were captured and analyzed with the Olympus IX73 and Image J software.