IL5 and breast cancer: Considering the elderly breast cancer patients, Kaplan-Meier survival analysis showed that patients whose CD4+ T-cells produced IL-5 tended to have poorer outcomes (p = 0.1, Fig. 2a) with a survival rate of 43 % compared to 73 % for patients whose CD4+ T-cells did not produce IL-5 when stimulated with Her-2 peptides.