Protein expression overview of known CySS transporters in various tissues. Using the Human Protein Atlas [59], the protein expression overview of CySS transporters b0,+AT and rBAT, encoded by the SLC7A9 (A) and SLC3A1 (B) genes, respectively, were visualized. The kidneys (orange bar) represent one of the tissues with the highest expression of SLC7A9 and SLC3A1. The skin, liver, lung, muscles, thyroid and other tissues minimally or do not express the same transporters. Only CySS transporter genes with available protein data for which a knowledge-based annotation gave conclusive results were included.