Interacting spinning fermions with strong quasi-random disorder are analyzed via rigorous Renormalization Group (RG) methods combined with KAM techniques. The correlations are written in terms of an expansion whose convergence follows from number-theoretical properties of the frequency and cancellations due to Pauli principle. A striking difference appears between spinless and spinning fermions; in the first case there are no relevant effective interactions while in presence of spin an additional relevant quartic term is present in the RG flow. The large distance exponential decay of the correlations present in the non interacting case, consequence of the single particle localization, is shown to persist in the spinning case only for temperatures greater than a power of the many body interaction, while in the spinless case this happens up to zero temperature. In recent cold atoms experiments [17] evidence of MBL has been reported. The disorder is not random (as in the above mentioned theoretical works) but quasi-random, but the theory of MBL can be developed also in that case [18]. The experiments use two laser beams with incommensurate frequencies, superimposing to a one dimensional lattice a periodic potential with a period that is incommensurate with the underlying lattice, producing a realization of an interacting Aubry-Andre' model [19]; subsequent experiments considered two coupled chains [20].Random or quasi random disorder have similar properties, at least for strong disorder. In particular, a strong incommensurate potential produces localization of the single particles eigenstates [21], [22], as in the random case, while for weak potential there is no localization. There is then a metal-insulator transition as for 3D random disorder (in 1D the eigenstates in the random case are instead always localized). Such properties are due to a close relation with the Kolmogorov-Arnold-Moser (KAM) theorem for the stability of tori of perturbed Hamiltonian systems. The simplest generalization of the Aubry-Andre' model to interacting fermions is the one with the following Hamiltonian