There is growing evidence that macrophages are capable of killing tumour cells [62] and our previous studies reporting that CD154-bearing macrophages are present in the human liver and can induce apoptosis in CD40-expressing cholangiocytes [63] suggests another mechanism through which CD40 could mediated anti-tumour responses in cholangiocarcinoma. The gene discussed is CD40LG; the disease is cholangiocarcinoma.