Phenomenological Meaning of a Neutrino Mass Matrix Related to Up-Quark Masses

Recently, a curious neutrino mass matrix has been proposed: it is related to up-quark masses, and it can excellently give a nearly tribimaxial mixing. It is pointed out that, in order to obtain such successful results, three phenomenological relations among masses and CKM parameters must be simultaneously satisfied. This suggests that there must be a specific flavor-basis in which down-quark and charged lepton mass matrices are simultaneously diagonalized.