To determine the role of RNase1 in the TME of breast cancer, we utilized a set of established stable clones 24, namely mouse 4T1 mammary tumor cells expressing mouse RNase1 (4T1-RNase1) and vector control (4T1-vector), and orthotopically implanted the cells into the mammary fat pad of immunocompetent BALB/c mice (Figure 1A). Here, RNASE1 is linked to breast carcinoma.