While recruitment of CD11b+ cells to metastatic tumor cells was extensive in pFN-competent C57BL/6-Fn(fl/fl) Mx-Cre− mice, we detected significantly less CD11b+ cells adjacent to tumor cells in lungs from pFN-deficient C57BL/6-Fn(fl/fl) Mx-Cre+ mice (Figure 1B,C). This evidence concerns the gene MX1 and neoplasm.