In this talk I present the Two-hadron saturation (THS) scenario for the PVV correlator and apply it to two important processes
of the low energy hadron physics: the Dalitz decay of pi0 and pi0 -> e+e-. Experimental and theoretical results on the rare decay
pi0 -> e+e- are briefly summarized. The notorious 3.3sigma discrepancy between the SM prediction and the experimental value 
provided by KTeV collaboration is discussed in the view of a complete set of NLO QED radiative corrections. 
The important contribution of analytical two-loop QED corrections together with the bremsstrahlung contribution beyond the 
soft-photon approximation are reviewed. Using the leading logarithm approximation, the possible contribution of QCD corrections 
is estimated. The discrepancy under discussion then reduces down to 1.8sigma. The obtained results can be also used in a theoretical
calculation of the hadronic light-by-light scattering contribution to the g-2 type experiments.