immune system

a serious (often fatal) disease of the immune system transmitted through blood products especially by sexual contact or contaminated needles

recipient's immune system must be suppressed to prevent rejection of the graft

any of various protein molecules secreted by cells of the immune system that serve to regulate the immune system

released by the human immune system during allergic reactions

immunological disorder in which some part of the body's immune system is inadequate and resistance to infectious diseases is reduced