The two best predictors, HORMAD1 and CT83, are strongly associated with basal breast tumors: of the 190 basal-like breast tumors, 89% expressed either HORMAD1 or CT83, compared to only 13% of Her2-amplified, 6% of Luminal B, and 2% of Luminal A tumors (Fig. 2D). The gene discussed is ERBB2; the disease is breast neoplasm.