Hang Pong Ng

1. Introduction Macrophages are major phagocytic cells of the innate immune system that play a critical role in maintaining tissue homeostasis and protecting the host from the deleterious effects of infections and injuries [1]. Macrophages sense the surrounding environment by an array of cell surface receptors, including pattern recognition receptors, scavenger receptors, Siglecs (sialic-acid-binding immunoglobulin-like lectins), and integrins.