Macrophages carry out various functions in the human immune system including: 

• Detection, phagocytosis and destruction of bacteria and other harmful microorganisms
• Maintaining homeostasis by clearing out debris, and old, senescent, or dead cells 
• Mediating reparative processes including muscle repair, growth, and regeneration after inflammation
• Initiating inflammation by releasing small signaling proteins called anti-inflammatory cytokines that activate other immune cells
• Presenting antigens to T cells 
• Facilitating wound healing by limiting the extent of inflammation and contributing to tissue repair and regeneration
• Maintaining iron homeostasis by acting as scavengers and continuously clearing out dead erythrocytes from blood, which leads to the accumulation of released iron in the form of ferritin