  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.
