To evaluate the cell type-specific roles of tumor cell-secreted HGFL on mammosphere/breast cancer stem cell formation, we co-cultured HGFL proficient and deficient R7 cells with WT (TK+/+) or with RON deficient (TK−/−) BMDMs, with or without rHGFL rescue (Figure 4C). This evidence concerns the gene MST1R and neoplasm.