CD28 and neoplasm: CD4+ T cells were sorted from tumors and tumor-draining lymph nodes of Tslp-PyMttg (test) or MMTV-PyMTtg, Tslpr(Crlf2)−/− (PyMttg TslprKO; control) mice and stimulated ex vivo using anti-CD3/CD28 antibodies plus TSLP over one to three cycles.