CUL4B and breast cancer: More importantly, to investigate the role of the RUNX2/NuRD(MTA1)/CRL4B complex in breast cancer in vivo, the primary tumorigenesis results showed that the volume of the primary tumor was significantly increased with the overexpression of RUNX2 but was inhibited by the simultaneous knockdown of MTA1 or CUL4B (Fig. 4B, Supplementary Fig. 4B).