IGFBP5 and breast cancer: To confirm that deletion of amino acids 214 to 218 within the NLS of IGFBP5 promotes breast cancer cell motility, we transiently transfected the MDA-MB-435 breast cancer cells with IGFBP5wt/pcDNA3.1(+) and IGFBP5mt/pcDNA3.1(+) constructs and performed the in vitro migration assay 48-h post-transfection.