2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/211425A simple relation U_{MNS}=V_{CKM}^\dagger U_{TB} between the lepton and quark mixing matrices (U_{MNS} and V_{CKM}) is speculated under an ansatz that U_{MNS} becomes an exact tribimaximal mixing U_{TB} in a limit V_{CKM}={\bf 1}. By using the observed CKM mixing parameters, possible values of neutrino oscillation parameters are estimated: \sin^2 θ_{13}=0.024-0.028, \sin^2 2θ_{23}=0.94-0.95 and \tan^2 θ_{12}=0.24-1.00 depending on phase conventions of U_{TB}. Those values are testable soon by precision measurements in neutrino oscillation experiments.8 pages, 3 figures, version to appear in Phys.Lett.BHigh Energy Physics - PhenomenologyTestable Deviation from Exact Tribimaximal Mixingtext