Elevated levels of activated ARF6 (ARF6-GTP) have been found to increase the invasive capacity of melanoma cells both in vitro (Tague et al. 2004) and in vivo (Muralidharan-Chari et al. 2009), while silencing ARF6 by small-interfering RNA inhibits the ability of breast cancer cells to invade through an artificial basement membrane, thereby providing evidence that ARF6 may be particularly important in driving tumour metastasis (Hashimoto et al. 2004). This evidence concerns the gene ARF6 and breast cancer.