CD4 and breast cancer: In breast cancer patients, prior to surgery and adjuvant therapy, a general immune system dysfunction favoring a Th2 response, was also found in comparison to healthy controls, as measured by the lower percentage of CD4+ and CD8+ T lymphocytes producing type 1 (lL-2, IFN-γ, or TNF-α) and type 2 (IL-4) cytokines [11].