**Acknowledgements**

This work was funded by project PI15/01803 [Instituto de Salud Carlos III (Ministry of Economy, Industry and Competitiveness) and cofunded by the European Regional Development Fund]; and by project Multimat Challenge (S2013/MIT-2862-CM, funded by the Regional Government of Madrid and EU Structural Funds), and approved by the Ethics Committee of our Institution.

The authors are very grateful to Ian Ure for proofreading the English version of this chapter.
