RAC1 and non-small cell lung carcinoma: In summary, our findings demonstrate that NSCLC cell-derived exosomal lncRNA-SOX2OT regulates osteoclast differentiation and promotes BoM of NSCLC cells by targeting the miRNA-194-5p-mediated RAC1 signalling pathway and regulating the TGF-β/pTHrP/RANKL signalling pathway in osteoclasts (Fig. 7).