RT-PCR products for hMSC/SELP-47 K in the absence (lanes 1–3) and presence (lanes 4–6) of TGF-β3 and cell pellets (lanes 7–9) cultured in the presence of TGF-β3 after 1, 14 and 28 days (D1, D14 and D28, respectively). Primers used include β-actin (housekeeping), type I collagen, aggrecan, type X collagen, type II collagen and SOX 9 (from top to bottom of the gel).