TPO and neoplasm: As presented by Ehlers et al., the tumour-protecting feature of TPOAb might be explained by (a) complement-mediated cell death, which is anti-TPO antibody-dependent because TgAb antibodies do not fix complement, and (b) TPOAb antibody-dependent cell toxicity due to the exclusive binding of anti-TPO antibodies to their effector cells via Fc-gamma receptor 1 (CD64), which is known to be expressed on monocytes (70).