  Collective flow as a consequence of hydrodynamical evolution in heavy ion
collisions is intensively studied by theorists and experimentalists to
understand the behavior of hot quark matter. Due to their large mass, heavy
ions suffer collective effects even at low (SPS) or intermediate energies
(RHIC). In case of light systems such as (anti)proton-proton interactions,
collective effects was not expected. Within a global model such as EPOS, where
light and heavy systems are treated using the same physics, it appears that
Tevatron data are better described if a flow is introduced. Then the
extrapolation to LHC can easily be done and we can compare to first data from
ATLAS experiment.
