REL and neoplasm: Similarly, we also overexpressed CUL4B in U2OS‐SPD304, U2OS‐TNFR1‐KD, U2OS‐TNFR1‐KD + RelA‐KD, U2OS‐TNFR1‐KD + RelB‐KD, and U2OS‐TNFR1‐KD + c‐Rel‐KD cells to determine whether CUL4B could reverse or partially rescue the decreased cell proliferation, colony formation ability, invasion, and in vivo tumor formation ability.