Effect of phenytoin on breast tumour growth. (A) Tumour section stained with (i) anti-Nav1.5 or (ii) anti-Nav1.7 (red) and DAPI (blue). T, tumour, F, fibroadipose tissue. Scale bar, 100 μm. (B) Phenytoin dosing protocol. BLI, bioluminescent imaging. (C) Weight of mice during the assay. (D) Bioluminescent images of control and phenytoin-treated mice, 4 weeks after implantation. (E) Bioluminescence measured from primary tumours on the indicated days post-implantation. (F) Calculated volume derived from calliper measurement of primary tumours over the same period. Data are mean ± SEM; *P < 0.05 (n = 13 for control, n = 15 for phenytoin).