AGXT and renal cell carcinoma: It was described that overexpression of the SPT subunit SPTLC3 leads to the production of sphingolipids with a C16 sphingoid base [10]. The atypical sphingolipid with a C16 base d16:1 S1P, was recently shown to mediate connective tissue growth factor (CTGF) induction via S1P2 in renal cell carcinoma (RCC).