Due to infection and tissue damage, IL-6 is produced rapidly by a variety of cells, including immune-mediated cells, mesenchymal cells, endothelial cells, fibroblasts and cancer cells, and even many other cells, which promotes host defense by stimulating acute phase reactions, hematopoiesis, and immune responses (Akira et al., 1993; Tanaka et al., 2014; Tanaka et al., 2016a). Here, IL6 is linked to infection.