The recent data by the Belle collaboration[1] is dramatically different from those reported by the BABAR collaboration,[2] i.e.instead of a pronounced growth of the TFF in high Q2 region,observed by BABAR,the Belle data are compatible with the well-known asymptotic prediction Q2Fπ γ (Q2)[Q2→ ∞→ x√2fπ,where the pion decay constant fπ =130.41 ± 0.03 ± 0.20 MeV.[3]One thinks that it would be a big challenge to QCD if the BABAR data are confirmed.One should ask a question what is the realistic light-cone wave function of the pion.Theoretically the pion-photon TFF depends heavily on the pion DA and sensitive to it in the higher energy region.Such large discrepancy between the Belle and the BABAR data in the high Q2 region shows that the pion-photon TFF cannot discriminate the different pion DA models.On the other hand,all the processes involving pion can provide more strong constraints on the pion DA for determining it.It would be helpful to have a general pion DA model that can mimic all the DA behaviors suggested in the literature.