C1QBP and breast cancer: gC1qR-positive cells generally localize to hypoxic or nutrient-deprived regions in tumor models, most notably in breast cancer, where the mitochondrial protein is overexpressed and located on the extracellular surface (Fogal et al., 2008; Song et al., 2019) gC1qR has also been implicated in atherosclerotic lesions, with a notable presence in activated macrophages (Peerschke et al., 2004; Song et al., 2019).