Here, we have examined the numbers of Treg cells, Th17, NK and NKT cells in Her-2/neu (HER2)-positive (early and metastatic breast cancer (MBC)) and HER2-negative breast cancer patients, with the aim of further elucidation of the role of Treg and Th17 cells, and their balance, in different patient populations with breast cancer over time. The gene discussed is ERBB2; the disease is breast cancer.