SLC39A4 and cancer: ZIP4 has been shown to have tumor promoting activities in several cancers [9,10,11,12,13], with a broad range of activities, including promoting resistance to apoptosis, cell proliferation, invasion, epithelial-to-mesenchymal transition, cytokine secretions, upreregulation of oncogenes, and tumor progression [9,10,12,13,47,78].