There is provided an antibody and an IL-21 polypeptide for use in treating cancer, wherein said antibody is selected from: (i) HuMax-CD20, alemtuzumab, and Zamyl (ii) an antibody against tissue factor, laminin-5, EGF receptor, VEGF receptor, PDGF receptor, HER-2/neu, prostate-specific antigen (PSA), prostate stem cell antigen (PSCA), carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), tumor-associated calcium signal transducer antigen (KSA), or VEGF (iii) an antibody that activates a TRAIL receptor or (iii) a monoclonal antibody against CTLA-4, leukocyte immunoglobulin-like receptor 1 (LIR), CD94, or NKG2A.
