WBCs, also known as leukocytes, are the mobile defense units of the body's immune system. They help protect the body from microbes and other foreign substances. There are different types of WBCs, with neutrophils being the most common at 50-70% of total WBC count. Neutrophils help fight infection through processes like phagocytosis, where they ingest and destroy microbes. During inflammation, neutrophils are recruited to sites of injury or infection through a process called the leukocyte adhesion cascade. Signs of inflammation include redness, heat, swelling, pain, and loss of function in the inflamed area. The number of neutrophils can increase or decrease depending on factors like infection or disease.