Figure 3.

Sequential steps during development of long bones. A, Different stages of endochondral ossification are shown schematically along with stage-specific ECM marker proteins; B and C, underlying signaling/growth factors (B) and transcription factors (C) that are responsible for the transition of the cells into the next differentiation stage and translation into required stage-specific matrix production are indicated below. [Reproduced from S. Grässel and R. Dreier 2011 Effect of cellular microenvironment and paracrine signals on chondrogenic differentiation of mesenchymal progenitor cells In: Singh SR, ed. Stem cells, regenerative medicine and cancer. Nova Science Publishers, New York, p 441–467 (236), with permission.]