Protein expressions of collagen II, aggrecan and CD24were analyzed by western blotting. Quantitative analysis was did for collagen II, aggrecan, CD24, KRT18, Basp1 and CD54 gene expression in micromass-cultured iPSCs after 3 weeks differentiation, * compare with undifferentiation group p < 0.01, # compare with NP cells p < 0.05. F-iPS-C: fibroblast derived iPS cells without differentiation; F-iPS-D: fibroblast derived iPS cells cultured with NP differentiation media; NP-iPS-C: NP cells derived iPS cells without differentiation; NP-iPS-D: NP cells derived iPS cells cultured with NP differentiation media.