Our novel findings of the mitosis-specific TRBP2, but not PACT, downregulation in human cancer cells of diverse tissue origin provide strong insights for the essential involvement of TRBP2 in the onset and progression of human malignancies and highlight the TRBP2 protein as a new and promising biomarker for the efficient and successful prognosis, diagnosis, and (radio-/chemo-)therapy of the disease. This evidence concerns the gene TARBP2 and cancer.