Anti-CSF1R antibodies that inhibit macrophage migration to the tumour have been effective in the treatment of murine malignancies; however, clinical trials have observed no therapeutic benefit in humans, indicating a differential physiological role or reliance on macrophage behaviour between mice and human disease.1,18,19 The influence of macrophages on tumour biology in human malignancies is not fully known as macrophages are also known to adopt unreactive senescent and quiescent states.20 This evidence concerns the gene CSF1R and neoplasm.