As expected, the larger cancer studies revealed more pleiotropic associations, with the exception of HER2-positive breast cancer, which yielded only 26 variants; in contrast, the melanoma and prostate studies showed comparatively more pleiotropic associations (385 and 356 variants, respectively) (Fig. 2b,d and Additional file 1: Table S15). The gene discussed is ERBB2; the disease is breast cancer.