PECAM1 and infection: The immunophenotyping analysis in this study revealed that there was no significant difference in the MSC surface markers (positive for CD29, CD44 and CD90 and negative for CD34, CD86 and CD31) before and after the pLenO-DCE vector lentivirus infection that was carried with the GFP + maker, and most MSCs remained stable and undifferentiated after lentivirus infection, suggesting that the infection of MSCs with the pLenO-DCE lentiviral vector did not affect the MSCs and that MSCs infected with the pLenO-DCE lentivirus encoding MK are a promising tool for gene therapy.