Transcription factor that promotes adipocyte differentiation and suppresses osteoblast differentiation in the bone marrow. Enhances the osteoclast-supporting ability of stromal cells. Binds with STAT3 the consensus sequence 5'-CTTCTGGGAAGA-3' of the acute phase response element (APRE). Transactivates several promoters including FOS, OSM and PPARG. Recruits a histone deacetylase complex (By similarity).