TRAF3 and breast cancer: In our previous study, we found that miR‐214 was significantly increased in bone specimens from breast cancer patients with osteolytic bone metastasis (OBM) as well as in osteoclasts from nude mice with human breast cancer xenografts during OBM development, which was accompanied by the elevated bone resorption.[10] TRAF3 is a vital regulator of type I interferons and cytokine production that regulates RANKL‐induced osteoclast formation.[11] TRAF3 has a negative regulatory role in osteoclastic precursors.