 Case studies of immunology have contributed to understanding the role of models and the structure of theory in the biomedical sciences (see the entry on  models in science).  For example, Schaffner provided detailed analysis of the clonal selection theory and the two-component theory of the immune response to elaborate his criticism of the classical view of scientific theories and to provide an account in which middle range theories, consisting of interrelated theoretical models, organize subject areas in biology (Schaffner 1980). A taxonomy of immune models (both conceptual and experimental) exhibit a mosaic of methodologies and theoretical ways in which information is obtained and integrated in this field (Baetu 2014). Furthermore, high throughput sequencing techniques and other “omics” approaches in immunology, like those of microbial ecology, are increasingly utilizing new analytical tools (cf. Huss 2014). In conjunction with systems biology approaches, these tools inspire engineering orientations, in which biological systems achieve robustness and stability through the same principles with which machines are built, namely using system controls (e.g., feedback), redundancy (e.g., gene duplication, alternative metabolic pathways), modular design (to minimize damage to local units), and structural stability (Kitano 2001: 18). Apart from serving as an exemplar of systems-based theories and models, immunology has also been employed to develop cognitivist models, elucidate conceptual and theoretical change in biology, and elaborate on contentious issues about reductionism and anti-reductionism.