(A) overexpression of GFP in 14 days induced ATDC5 cells by retrovirus. (B) retrovirus-mediated overexpression of Runx1 in ATDC5 cells. (C) Western blot was performed on day 14 cultured chondrocytes to evaluate the protein levels of osteoblast genes and Ihh signaling-related genes. (D) Quantification of protein levels in C. All data are presented as mean ± SD, n=4, NS denotes not significant, *p<0.05, **p<0.01, ***p<0.001.