PRF1 and neoplasm: In this study, we observed that CD8+ T cells in tumor-bearing mice following bortezomib administration not only showed increased Notch1/2 activation but also sustained increased expression of T cell activation molecules CD25 and CD44, with significantly improved production of IFNγ and expression of eomesodermin, perforin and granzyme B. Eomesodermin is not only important for the differentiation of cytolytic CD8+ T cells but also helps maintain memory CD8+ T cell repertoire [59].