FGF1 and osteosarcoma: Since we have shown that the nuclear localization of FGF1 (whether translocated or ectopically expressed) is not responsible for its anti-apoptotic response in differentiated cells, such as human osteosarcoma (U2OS) and mouse fibroblasts (NIH 3T3), we hypothesize that the mode of action of FGF1 is more complex and may vary depending on the cell type it affects.