MIF and neoplasm: MIF is a cytokine produced by T lymphocytes, macrophages, and tumor cells, and its expression is associated with cell proliferation, cell cycle entry, angiogenesis, and tumorigenesis, resulting in antigen-specific immune responses between 131I-anti-MIF McAb and MIF, while uptake of 131I-IgG control group in tumor tissues is caused by nonspecific binding to Fc fragments of normal IgG.