RT Journal Article SR Electronic T1 Potassium channels of T lymphocytes take center stage in the fight against cancer JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP 2 DO 10.1186/s40425-016-0202-5 VO 5 IS 1 A1 Laura Conforti YR 2017 UL http://jitc.bmj.com/content/5/1/2.abstract AB A recent study by Eil at al. published in Nature in September 2016 provides evidence that alterations of the K+ homeostasis of tumor infiltrating lymphocytes (TILs) in necrotic areas of the tumor microenvironment (TME) suppress the function of effector T cells. Furthermore, they establish that overexpression of K+ channels in T lymphocytes counterbalances this negative effect of the TME and restores the ability of TILs to function, ultimately leading to increased survival of tumor bearing mice. Thus, K+ channels in T lymphocytes become interesting new targets for novel immunotherapies in cancer. This Commentary discusses Eil’s finding in the context of the central role that K+ channels play in the suppressed state of TILs as they mediate the immunosuppressive effects of multiple conditions of the TME including hypoxia and adenosine.Abbreviations:TMETumor microenvironmentTh1Type 1 helper T cellsTILsTumor infiltrating lymphocytesIL-2Interleukin 2IFNγInterferon gammaMHCMajor histocompatibility complexK+Potassium ionsTCRT cell receptorAktAKT serine/threonine kinase also known as protein kinase B or PKBmTORMammalian target of rapamycinPP2AProtein phosphatase 2ATregRegulatory T cellsKv1.3Voltage-gated potassium channel encoded in humans by the KCNA3 geneKCa3.1Calcium-activated potassium channel encoded in humans by the KCNN4 gene, also known as IK1 or Gardos channelNF-ATNuclear factor of activated T cellsCa2+Calcium ionsCTLA-4Cytotoxic T-lymphocyte associated protein 4PD-1Programmed cell death protein 1