BMI1 was detected to rapidly recruit to DNA lesions caused by local micro-irradiation via ultraviolet laser, ionizing irradiation (IR), and the replication fork stalling agent hydroxyurea (HU) in a number of cell types, including U2OS osteosarcoma cells, mouse embryonic fibroblasts (MEFs), HeLa, and CD133+ glioblastoma multiforme (GBM) cells [176,179,180,181]. Here, BMI1 is linked to osteosarcoma.