  The interference effect between leptonic radiative corrections and hadronic
polarization functions is calculated via optical theorem for $\mu-$pair
productions. It is achieved within the use of the last data for
$\sigma_h(e^+e^-\rightarrow hadrons)$ from SND,CMD,CMD-2,BABAR and BESSIII
experimental Collaborations. The paper takes into account specific experimental
conditions and the result is compared with KLOE experiment for $\mu^{-}\mu^{+}$
production at $\phi$ meson energy. Small, but non-negligible tension between
theory and experiment is discussed.
