ITGAM and neoplasm: Here, we show that upon recruitment, these cells are endowed with an enhanced ability to induce metastatic SCA1+ cells via a positive amplification mechanism: recruited Gr1+CD11b+ cells are tumor educated to elevate IL-6/OSM expression, which, in turn, induces SCA1+ cells with enhanced capacity to form metastases from low metastatic SCA1– cells.