Let us finish this Section with a brief discussion of the ab initio calculations for light nuclei. By using the Green Function Monte Carlo (GFMC) methods, one is able to determine binding energies, and energies of low-lying excited states, for systems containing up to =10 nucleons Pie02,Wir02. When the Argonne v NN potential is used in such calculations, all light nuclei come out significantly underbound, see Fig. 7. The most plausible reason for such a discrepancy is the absence of the three-body NNN interaction, which is, as discussed in Sec. 3.1, expected to be a natural component of the force, and incorporates the polarization effects of the quark-gluon structure of the nucleons. Unfortunately, the scattering data only give us information on the binary NN component, and the three-body piece has to be postulated independently. When the Illinois NNN interaction Pie01a is added, the GFMC calculations reproduce properties of light nuclei with a very good precision (Fig. 7).