The "système réticulo-endothélial" (reticuloendothelial system) refers to a network of cells and tissues in the body that play a crucial role in the immune response. It primarily consists of macrophages, monocytes, and endothelial cells found in various organs, including the liver, spleen, and lymph nodes. These cells help filter out pathogens and dead cells from the bloodstream. This system is essential for maintaining homeostasis and protecting the body from infections. It aids in the removal of foreign substances and contributes to the body's overall defense mechanisms. The reticuloendothelial system is vital for both innate and adaptive immunity.