As we have demonstrated previously in the B16 melanoma system, we have now demonstrated in mammary carcinoma that culturing B/I-activated lymphocytes from tumor-sensitized mice in IL-7/15/21 results in a much higher yield of viable cells than those grown in IL-2, IL-21, IL-2/21 and even IL-7/15. The gene discussed is IL7; the disease is breast carcinoma.