SLC39A4 and cancer: Then, four zinc transporter genes—ZIP4 (SLC39A4), ZIP6 (SLC39A6), ZIP7 (SLC39A7), and ZIP10 (SLC39A10)—were selected based on their documented roles in cancer-related signalling pathways, such as MAPK, PI3K/AKT, and epithelial-to-mesenchymal transition (EMT).