Alanine, serine, cysteine-preferring transporter 2 (ASCT2), encoded by SLC1A5 in humans, is a member of SLC family proteins that mediates uptake of Gln, which becomes a conditional EAA in the highly proliferative cancer cells [5,6] and supports intracellular amino acid homeostasis maintaining the activity of mTOR signaling pathway [6,34]. The gene discussed is SLC1A5; the disease is cancer.