 The second conceptual shift addresses how immunity mediates the interactions of the organism with its environment. That ecological orientation has inflected immunology from its earlier insular conceptions of the organism to a dynamic interactive view that highlights how life experience alters the immune response to external challenges and opportunities. With this broadened perspective, the idea of immunity extends beyond defense of an atomistic individual, to include the mediation of the organism’s ecological economy, both defensive and assimilative. This includes the internal environment as well, inasmuch as the microbiome, established through immune niche formation, has increasingly focused attention on the prevalence of immune tolerance, symbiosis, and the biology characterized by cooperative relationships of various sorts (Eberl 2010; Bilate and LaFaille 2012).