  Star-forming regions have been proposed as potential Galactic cosmic-ray
accelerators for decades. Cosmic ray acceleration can be probed through
observations of gamma-rays produced in inelastic proton-proton collisions, at
GeV and TeV energies. We analyze more than 11 years of Fermi-LAT data from the
direction of Westerlund 2, one of the most massive and best-studied
star-forming regions in our Galaxy. The spectral and morphological
characteristics of the LAT source agree with the ones in the TeV regime (HESS
J1023-575), allowing the description of the gamma-ray source from a few
hundreds of MeV to a few tens of TeVs. We will present the results and discuss
the implications of the identification with the stellar cluster and the
radiation mechanism involved.
