As shown in Fig. 2A, RelA, RelB, and c‐Rel mRNA species were significantly up‐regulated in all four osteosarcoma cell lines compared to hFOB1.19 cells, with the highest expression being observed in c‐Rel (~eightfold), and similar effects were observed in RelA and RelB (~sixfold). Here, RELB is linked to osteosarcoma.