Furthermore, in some Grand Unification Theories (GUTs) the direct QLC correlation between the CKM and the PMNS mixing matrix can be obtained. In this class of models, the  matrix is determined by the heavy Majorana neutrino mass matrix.
Furthermore, in some Grand Unification Theories (GUTs), a relationship between the CKM and PMNS mixing matrices can be established through the QLC correlation. In this context, the  matrix is specified by the massive Majorana neutrino mass matrix.