CTLA4 and lymphoma: Using a variety of immunocompetent, syngeneic mouse tumour models (BCL1 lymphoma, A31 lymphoma Eμ-TCL1 B-cell leukaemia and B16 melanoma), and a panel of immunomodulatory mAbs (e.g. CTLA4, PD1, PDL1, 4-1BB, OX40 and GITR mAbs), we demonstrated that only anti-CD27 significantly enhances the efficacy of anti-CD20.