Expression of CXCR3, the MIG receptor, in osteoclast precursors and differentiating osteoclasts incubated with M-CSF. (A) Osteoclast precursors were stimulated with 50 ng/mL M-CSF or 50 ng/mL M-CSF plus 100 ng/mL RANKL for the indicated time. Total RNA was extracted from the treated cells and subjected to RT-PCR analysis with CXCR3 or GAPDH primers. (B) Cells were prepared as described in panel A. The presence of CXCR3 on the cell surface was analyzed by flow cytometry, as described in “Materials and methods.”