SCN5A and neoplasm: High Nav1.5 protein expression was correlated with larger tumour size (P < 0.001; Mann–Whitney U test; Fig. 1B), lymph node positivity (P < 0.05; Mann–Whitney U test; Fig. 1C), higher Nottingham prognostic index (P < 0.001; Mann–Whitney U test; Fig. 1D), and higher tumour grade (P < 0.001; χ2 test; Table 1).