Related to Fig. 2. a, Migration in transwell invasion assays of three melanomas treated with DMSO (control) or AZD3965 (MCT1 inhibitor), including representative images (left) and counts (right) of the cells that migrated across the insert after 24 h (one experiment with two to three replicate cultures per melanoma). b, c, Effect of acute treatment with AZD3965 (7 days) on the diameter of subcutaneous tumours, the frequency of circulating melanoma cells in the blood and metastatic disease burden in mice with established M481 (b) or M405 (c) melanomas. Treatment was initiated when the subcutaneous tumours reached 2 cm in diameter (one experiment per melanoma with three mice per treatment). d, Efficiently metastasizing melanoma cells (M405) were subcutaneously transplanted into mice and allowed to spontaneously metastasize; then the primary tumours were resected to prolong survival and to allow the metastatic tumours that had formed before primary tumour resection to grow larger. Mice were treated with AZD3965 for the duration of the experiment, only before primary tumour resection, or only after primary tumour resection. e, Analysis of total metastatic disease burden at end point showing that metastatic disease burden was reduced when AZD3965 treatment was performed before primary tumour resection, during the time when melanoma cells were spontaneously metastasizing, but before metastatic tumours were established. The number of mice per treatment is shown (two independent experiments). Data are mean ± s.d. Statistical significance was assessed using two-way ANOVA followed by Dunnett’s multiple comparison’s adjustment (a), t-tests (b, c) or Kruskal–Wallis test followed by Dunn’s multiple comparison’s adjustment (e). Source Data