  We analize two reactions: the electroproduction at small x and the Drell-Yan
production by protons on nuclei. We show that nuclear shadowing in
electroproduction is larger if the virtuality of inter- mediate hadrons is
properly taken into account. In the Drell-Yan production, initial state
interactions of fast partons are included. With this input, the excess pion
contribution improves the description of data for both reactions.
