FOSL1 and breast cancer: Tumor-derived IL-6 downregulated the expression of miR-19a-3p in Tumor-Associated Macrophages (TAMs), polarizing them towards an immune-suppressive phenotype (M2-polarization) by increasing the expression of FOS-related antigen 1 (Fra-1) and finally promoting migration and invasion of 4T1 breast cancer cells [150].