  A state-of-the-art analysis of the pion-photon transition form factor is
presented based on an improved theoretical calculation that includes the effect
of a finite virtuality of the quasi-real photon in the method of light-cone sum
rules. We carry out a detailed statistical analysis of the existing
experimental data using this method and by employing pion distribution
amplitudes with up to three Gegenbauer coefficients $a_2, a_4, a_6$. Allowing
for an error range in the coefficient $a_6\approx 0$, the theoretical
predictions for $\gamma^*\gamma\to\pi^0$ obtained with nonlocal QCD sum rules
are found to be in good agreement with all data that support a scaling behavior
of the transition form factor at higher $Q^2$, like those of the Belle
Collaboration. The data on $\gamma^*\gamma\to\eta/\eta'$ from CLEO and \babar
are also reproduced, while there is a strong conflict with the auxetic trend of
the \babar data above 10 GeV$^2$. The broader implications of these findings
are discussed.
