This NLS is believed to mediate the translocation of IGFBP-5 to the nuclear compartment as IGFBP-5 was detected in the nucleus of the breast cancer cell line T47D, lung fibroblasts from patients with IPF, vascular smooth muscle cells and osteosarcoma cells [2, 7, 9–11]. This evidence concerns the gene IGFBP5 and breast cancer.