['Mesenchymal stem cells are a population of pluripotent cells that can differentiate into epidermal-like cells under certain conditions. Wnt3a can promote the proliferation and differentiation of stem cells. However, the role of Wnt3a in the differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs) into epidermal-like cells is unknown.', 'Third-generation hUCMSCs were cultured in normal medium, epidermal stem cell-conditioned medium, and conditioned medium with added Wnt3a. After culturing for 5 days, the expression of cytokeratin 19 (CK19), an antigen specific for epidermal-like cells, was assessed by immunofluorescence and flow cytometry. The expression of CK19 mRNA was confirmed by reverse transcription-polymerase chain reaction(RT-PCR), and β-catenin expression was detected by western blot.', 'hUCMSCs differentiated into epidermal-like cells when cultured in conditioned medium as shown by positive immunofluorescence staining for CK19. Flow cytometry showed that the number of cells positive for CK19 in the epidermal stem cell-conditioned medium group was significantly higher than that of control group, but lower than that of the Wnt3a-conditioned group (p < 0.05). RT-PCR showed that the expression level of CK19 mRNA in the conditioned medium group was significantly lower than that of the Wnt3a group (p < 0.01). Westernblots showed that the expression of β-catenin in the conditioned medium group was significantly lower than that of the Wnt3a group (p < 0.01).'] Does wnt3a promote human umbilical cord mesenchymal stem cells to differentiate into epidermal-like cells?