We report one a first study of 4-jet production in a complete high-energy
factorization (HEF) framework \cite{Kutak:2016mik,Kutak:2016ukc}. We include and discuss contributions
from both single-parton scattering (SPS) and double-parton scattering
(DPS) and compare to the measured data.
The DPS HEF result is
considerably smaller than the one obtained with collinear
factorization. The mechanism leading to this difference is of
kinematical nature. In
contrast to the collinear approach, the HEF approach nicely describes
the distribution of the $\Delta S$ variable, which involves all four
jets and their angular correlations.