SLC38A7 and osteosarcoma: Within osteosarcoma (Figure 1a) we identified that cells have higher expression of the SLC7A1 and SLC7A2 amino acid transporters, compared to the SLC7A3 and SLC7A4 transporters (Figure 1a) consistent with the established role of these isoforms in transporting arginine and other key amino acids such as lysine and ornithine.