PIM2 and osteosarcoma: To test whether the cell growth retardation and increased apoptosis upon over-expression of the 34 kDa PIM-2 isoform, is unique to HeLa cells, we constructed a stable Tet-on-inducible system in U2OS cells (human osteosarcoma) in which expression of either HA-PIM-2, or HA-PIM-2KD are activated by Doxycycline (Dox).