WNK2 and cancer: Indeed, Arf1 is upregulated in cancer cell types and plays a role in cancer metastasis phenotypes e.g. cell detachment, migration and invasion, and may additionally be involved in tumour-promoting cell signalling pathways e.g. the phosphatidylinositol 3-kinase (PI3K) and mitogen-activate protein kinase (MAPK) pathways6–9.