CHRNA5 and neoplasm: CHRNA5 expression was higher in neoplastic tissues of current smokers than that of lifelong non-smokers (p < 0.01; Fig. 5B) and increased with increasing grade (p < 0.05; Fig. 5C), TNM stage (p < 0.05; Fig. 5D) and tumour size (p < 0.01; Fig. 5E).