ERBB2 and breast cancer: Raw264.7 cells are derived from the ascites of an Abelson murine leukemia virus‐induced tumor in a male BALB/c mouse, displaying a spectrum of biological activities that render it a prominent tool for simulating and investigating diverse functionalities and responses inherent to macrophages.[74] Researchers devised HER2‐CAR‐modified Raw264.7 cells, which, upon co‐culture with HER2+ human breast cancer cells, effectively triggered the expression of matrix metalloproteinases (MMPs) within macrophages.