IL2 and breast cancer: 45 pts were treated. Dose-related toxicity from TRZ was not observed. IL-2-related toxicities such as fever, chills, and fatigue were less common with the reduced doses of IL-2. There were two grade 3 and three grade 4 pulmonary reactions. 4 major responses were observed, all in BC pts treated with TRZ doses of at least 4.0 mg/kg