JAK3 and neoplasm: We observed that, of the Jak proteins and associated Stat proteins, phosphorylations of Jak-3 and Stat-5 were down regulated in CD4+ T cells (Fig. 3B–C) by tumor-shed PGE2 (Fig. 2A), which could be ameliorated by pre-treatment of the tumor cells with theaflavins (Fig. 3B–C).