Figure 5: Effects of AXL receptor deregulation on OPG synthesis showed that (a) receptor antagonist increased OPG levels by 7 d on all surfaces compared to control osteogenic medium alone. The levels were statistically highest on antagonist-rough cultured cells. (b) Receptor antagonist similarly affects levels of soluble GDF-15 compared to osteogenic medium only control. However, changes were not statistically significant. Bars show mean ± SEM; N=3, n=3. a=p<0.05, control vs. any of the two conditions. b=p<0.05, agonist vs. antagonist.