C1QA and melanoma: C1q protein (composed of C1QA, C1QB, and C1QC) expressed by mesenchymal cells and immune cells in melanoma by IHC [46]C1qa-/- mice have slower melanoma tumor growth, prolonged survival, decreased tumor angiogenesis, and decreased lung metastasis [46]C1q from non-bone marrow-derived cells promotes accelerated melanoma tumor growth [46]C1q promotes cell adhesion, migration, and proliferation of melanoma cells [46]