 The self/nonself, tolerance/response dichotomies collapse altogether, when considered in the context of mammalian pregnancy, where various modalities are employed to preserve the temporary immune sanctuary of the ‘foreign’ fetus (Howes 2007; A. Martin 2010). Studies of immune-mediated exchanges between the mother and the fetus not only challenge our view of immunity as concerned with rejection and defense, but also transform our understanding of biological individuality (Erlebacher 2013; Howes 2008). More specifically, recent studies undermine the vision of the maternal immune system as antagonistic to the fetus and rather point to active immune participation in the formation of an amalgamated maternal-fetal individual, whose ontological status lies at the continuum between unification and distinctiveness (Howes 2008). Delineation of the role of inflammation during blastocyst implantation further supports this interactive vision, demonstrating that instead of acting as a rejection response, inflammation promotes a mutually tolerant fusion between the embryo and the mother (Griffith et al. 2017; Mor, Aldo, and Alvero 2017). Indeed, the transformation of an inflammation-induced reaction pathway into a cell differentiation pathway in decidual stromal cells exhibits the intimate connection of the immune and reproductive systems in eutherians (G. Wagner, Erkenbrack, and Love 2019; Nuño de la Rosa, Pavlicev, and Etxeberria 2019, in Other Internet Resources).