To determine whether YB-1 is full length or cleaved upon nuclear translocation we transfected three cancer cell lines (A549, H1299 and Saos-2) with a plasmid carrying both N- and C-terminal labels (HAYB-1FLAG, Supplementary Figure S1A) and quantitated the location of each tag using IF labelling of tag-specific antibodies. This evidence concerns the gene YBX1 and cancer.