LAT1 is a reciprocal transporter which imports essential amino acids, such as leucine, in exchange for efflux of other normally abundant amino acids, such a glutamine.40 However, cancer cells have high requirements for nutrients, making glutamine a conditionally essential amino acid in many cancers.11 This means that the levels of intracellular glutamine regulate the ability of LAT1 to promote growth of endometrial cancer cells. This evidence concerns the gene SLC7A5 and cancer.