CBFB and osteosarcoma: In normal human cells, the expression of CDK11 is tightly regulated; for example, in the normal human osteoblast cell lines HOBc and NHOst, there are extremely low or almost undetectable levels of CDK11, while CBFβ levels are correspondingly low in normal human osteoblast cell lines and exhibit high expression in osteosarcoma cell lines (Fig. 2c).