CCL13 and neoplasm: In terms of gene expression changes, there was increased gene expression of MARCO (p < 0.01), a scavenger receptor found on a subset of tumor-associated macrophages, and CCL13 (p < 0.01), a chemokine that serves as a chemoattractant for monocytes and T cells, and decreased expression of ALDOA (p < 0.01) following trastuzumab treatment (Figure 3C).