Question: The spleen is part of what system in the human body?
Disambiguated questions and answers: question: The spleen is part of what major systems in the human body?
The spleen is center of activity of what specific immune system in the human body?
answer: Lymphatic system
Immune system (Lymphatic system)
immune system
MPS
macrophage system
mononuclear phagocytic system (MPS)
reticuloendothelial system
mononuclear phagocyte system
mononuclear phagocytic system
Natural Questions answer: immune system (from the Wikipedia article "Spleen")