CD4 and melanoma: Zhou et al. [27] demonstrated that shRNA-mediated inhibition of PPP2R2D, a regulatory subunit of PP2A enhances the proliferation, cytokine production, and cytotoxic functions of adoptively transferred effector CD4 or CD8 T cells and tumor-infiltrating lymphocytes (TILs) augmenting antitumor immunity in B16-OVA melanoma model.