MyD88 is a protein that plays a crucial role in the immune system. It acts as an adaptor molecule that helps transmit signals from various receptors, particularly those involved in recognizing pathogens. When these receptors detect harmful invaders, MyD88 activates a series of downstream signaling pathways that lead to an immune response. This protein is essential for the function of several types of immune cells, including macrophages and dendritic cells. By facilitating the production of inflammatory cytokines, MyD88 helps the body respond effectively to infections and maintain overall health.