Cells are committed to an osteoclast lineage by c-Fos induction, but Jun proteins are not involved in the rescue of osteoclastogenesis.

The expression of c-Fos, Fra-1, c-Src, CTR, and G3PDH was examined in c-Fms⁺RANK⁻ cells cultured for 6 days with M-CSF and sRANKL (A); M-CSF, sRANKL, and GM-CSF (B); and M-CSF, sRANKL, GM-CSF, and IFN-α/β (C). NC indicates no template control. Expression of Fra-1, c-Src, and CTR was observed following induction of c-Fos.