CD80 and osteoarthritis, hip: Based on multiplex immunohistochemistry, femoral heads from GONFH patients, but not from patients with hip osteoarthritis, showed greater abundance of M1 macrophages (identified based on expression of CD68 and CD80 but no expression of CD206) at the necrotic area and greater abundance of M2 macrophages (identified based on expression of CD68 and CD206 but no expression of CD80).