Luciferase imaging on day 21 showed that DMS-53 lung tumour growth decreased in mice treated with D2R agonist quinpirole relative to that in vehicle-treated control mice (Fig. 1b, c; Supplementary Fig. 1), supporting the hypothesis that D2R agonists inhibit SCLC growth in an orthotopic mouse model of human SCLC. This evidence concerns the gene DRD2 and small cell lung carcinoma.