As a proof of principle that TRAIL-Rs on TAM constitute an interesting molecular target to induce their apoptosis, we treated tumor-bearing mice with recombinant TRAIL and observed a significant decrease of TAM and of circulating monocytes; even if tumor cells were completely resistant to TRAIL-induced apoptosis, a significant slow down of primary tumor growth was noted, as well as a reduction in the number of spontaneous lung metastasis. Here, TNFSF10 is linked to neoplasm.