MIG protein expression stimulated by RANKL. Osteoclast precursors were treated with 50 ng/mL M-CSF or 50 ng/mL M-CSF plus 100 ng/mL RANKL for the indicated time (A) or were incubated with 50 ng/mL M-CSF plus the indicated concentration of RANKL for 24 hours (B). Cell lysates were prepared and subjected to Western blot analysis with anti-MIG antibody. The same membrane was stripped and reprobed with antiactin antibody. (C) Osteoclast precursors were treated with 100 ng/mL RANKL or 1 ng/mL IFN-γ for 24 hours. MIG concentrations in culture supernatants were determined using ELISA as described in “Materials and methods.”