  The high-energy QCD factorization for Deep Inelastic Scattering and for
proton-nucleus collisions using Wilson line formalism and factorization in
rapidity is discussed. We show that in DIS the factorization in rapidity
reduces to the $k_{\rm T}$-factorization when the 2-gluon approximation is
applied, provided that the composite Wilson line operator is used in the
high-energy Operator Product Expansion. We then show that the inclusive forward
cross-section in proton-nucleus collisions factorizes in parton distribution
functions, fragmentation functions and dipole gluon distribution function at
one-loop level.
