SLC16A1 and cancer: To maintain an enhanced glycolytic flow, GBMs require the rapid outflow of lactic acid into the tumor microenvironment (TME), facilitated by a series of plasma membrane transporters called monocarboxylate transporters (MCTs) (6); among these, only four (MCT1–4) are known to play a role in lactic acid transport in mammalian tissues, including cancers (7), and MCT1 and MCT4 have been implicated in multiple aspects of GBM progression, including angiogenesis, cell proliferation, and immunity modulation (8).