(A) Schematic display of Ihh promoter region (−3919 to +270): TSS, predicted Runx1-binding sites, and ChIP primers positions. (B) ChIP analysis of Runx1 binding to the Ihh promoter in ATDC5 cell line induced 7 days using primers as indicated on the x-axis. Results are presented as ChIP/Input. (C). Agarose gel image using ChIP qPCR products in (B). (D) Ihh promoter fragments were inserted into pGL3-basic vector. ATDC5 cells were co-transfected with pGL3-Ihh −84bp, −456bp, −1280bp and Runx1. Luciferase was detected at 48 hours post transfection and normalized to β-gal activity. All data are presented as mean ± SD, n=4, NS denotes not significant, ***p<0.001.