MARCO and neoplasm: In PB of humans with metastatic/recurrent triple-negative BC and high-grade serous OC, we also detect a significant increase of CSF1R+ CD68+LDLR+ BMBP, which also express the macrophage-specific genes Cebpa, Cebpb, and Marco. Importantly, the B-MF signature is also identifiable within unique macrophage clusters using recently published scRNA-seq profiles of tumor-infiltrating cells in patients with BC38 and high-grade serous OC39.