[en] We highlight some of the progress made in understanding the EMC effect and the NuTeV anomaly using a chiral effective theory of QCD, that is, the Nambu-Jona-Lasinio model. A natural consequence of this approach is that for nuclear systems the mean scalar and vector fields couple to the quarks inside the bound nucleons and therefore nucleon properties are modified in the medium. In particular, we demonstrate that the medium modification of nucleon quark distributions provides a natural explanation of the EMC effect. We also illustrate how a proton-neutron asymmetry in nuclei leads to an isovector-vector mean-field which couples to the quarks in the bound nucleons and that this mechanism leads to an additional correction to the NuTeV measurement of sin² θ_w.