Fig. 5. Validation of differentially expressed marker genes by real-time PCR. The mRNA expression levels of COL-I, ALP, OCN, BMP-2, RUNX-2 were measured with RT-Q-PCR. Under most circumstances, TNF-α down-regulated the mRNA levels of the six genes and it returned to a relatively higher level (p < 0.05) with the presence of PLX-4720.