IL10 and lymphoma: The levels of IL‐10, considered to be an anti‐inflammatory cytokine, were measured in serum from three healthy donors and malignant exudates from 12 patients with peritoneal (A) or pleural (P) malignancies (seven peritoneal ascites—six ovarian and one breast; five pleural—one colorectal, one lymphoma, one lung and two epithelioid mesothelioma).