Healthy individuals and HER2-negative breast cancer patients had similar Th17 numbers, and in an inverse relationship than that observed in Treg cells, HER2-positive patients had significantly lower frequencies of Th17s compared with healthy and HER2-negative individuals (0.314% compared with 0.748% (P=0.014) and 0.84% (P=0.0088), respectively). The gene discussed is ERBB2; the disease is breast cancer.