SLC9A1 and central nervous system cancer: Labeling of MCT1, which can transport lactate and H+ either out of or into cells [64], peaked near the rim (Fig. 2D); the average distance of the MCT1 peak from the edge was 1.05±0.14 mm (9 gliomas) significantly greater than the distance of the NHE1 peak (P = 0.0001).