IL1B and infection: In line with the observation that P2RX7 predominantly expresses in the immune cells/organs, activated P2RX7 by extracellular ATP following tissue injury or infection has been evidenced to play a central role in mammalian innate immune responses through the secretion of pro-inflammatory cytokines IL-18 and IL-1β [4], induction of apoptosis [11], generation of reactive oxygen and nitrogen intermediates [12] and stimulation of phagosome–lysosome fusion [13].