CUL4A and osteosarcoma: Consistently, western blot (WB) analysis also indicated that the CUL4B protein was significantly induced (~3–4-fold induction) in all four osteosarcoma cell lines and that CUL4A was slightly overexpressed (~1.3–1.6-fold induction), whereas other Cullin family proteins were not (Fig. 1B, Supplementary Figure 1A).