It is known that Gln, Asn and His are substrates of the so called “N system” transporters (88), such as SNAT3, SNAT5 and SNAT7 (89, 90), but little information is available on the expression of these transporters in cancer tissues, and no attempt has been made thus far to correlate their expression with that of ASNS. The gene discussed is SLC38A7; the disease is cancer.