These results were strengthened by a follow up study with our established shSep15 murine colon cancer cell line, which demonstrated that GBP-1 mRNA is also inducible through targeted down-regulation of Sep15 in vitro. Furthermore, in the NCI-60, a collection of 60 human cancer cell lines routinely used for screening and comparative analyses, the Sep15 gene is significantly correlated with GBP-1 (Pearson’s correlation, p<0.05), and also with its isoforms GBP-2, GBP-3 and GBP-4 (http://discover.nci.nih.gov/cellminer± database version 0.9). This evidence concerns the gene GBP4 and cancer.