Human and murine M-CSF, sRANKL and TNF were purchased from Peprotech (Rocky Hill, NJ). I-BET was synthesized by GlaxoSmithKline (UK) as previously described15 (link),51 (link),52 (link). MYC inhibitor 10058-F4 was purchased from Sigma-Aldrich. The MTT assay kit was purchased from Roche, and cell viability was measured following the manufacturer’s instructions. The antibodies (1:1000) used for immunoblotting are as follows: NFATc1(BD Pharmagen; 556602); c-myc and p38 (Santa Cruz Biotechnology; sc-764 and sc535); Lamin B (Abcam; ab16048); phospho-ERK, IκBα, phospho-p38 and Blimp1 (Cell Signaling; 9101, 9242, 9215, 9115).