SLC9A1 and cancer: Moreover, through SCN5A gene silencing experiments using siRNA or short hairpin RNA in stable colon cancer cell lines, we identified that the SLC9A1 gene is also significantly downregulated (Figure 7e,f), suggesting that the relationship between these proteins is not only through a physical interaction with a pro-invasive role in cancer cells, but probably also through mechanisms of co-regulation of transcript expression.