  "Static" structure functions are the probabilistic distributions computed
from the square of the light-front wavefunctions of the target hadron. In
contrast, the "dynamic" structure functions measured in deep inelastic
lepton-hadron scattering include the effects of rescattering associated with
the Wilson line. Initial- and final-state rescattering, neglected in the parton
model, can have a profound effect in QCD hard-scattering reactions, producing
single-spin asymmetries, diffractive deep inelastic scattering, diffractive
hard hadronic reactions, the breakdown of the Lam-Tung relation in Drell-Yan
reactions, nuclear shadowing, and non-universal nuclear antishadowing--novel
leading-twist physics not incorporated in the light-front wavefunctions of the
target computed in isolation. I also review how "direct" higher-twist processes
-- where a proton is produced in the hard subprocess itself -- can explain the
anomalous proton-to-pion ratio seen in high centrality heavy ion collisions.
