SLC1A5 and neoplasm: Studies in tumor cell lines have shown that synthetic sphingolipids such as C2 ceramide block nutrient access by disrupting membrane trafficking of nutrient transporters such as SLC2A1, SLC16A1, SLC16A3, SLC1A5 and SLC7A5 by activating the serine and threonine protein phosphatase 2A (PP2A)28–30.