in deep inelastic scattering (DIS) and hadron-hadron collisions. Here, the nonperturbative component is parametrized in terms of parton distribution functions (PDFs) which undergo Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations. The key feature of PDFs is the *universality*, i.e. the PDFs that are measured in one process can be used in any other for which the factorization holds. Therefore, for instance one can use PDFs fitted to DIS structure functions and use them to make predictions for jets in hadron-hadron collisions. Although the collinear factorization is powerful and well-tested, it is supposed that for certain observables, e.g. forward jets at high energies, another kind of evolution equations for the PDFs is needed. Namely, the perturbative calculations contain the logarithms of the form $\alpha_{s}\log(1/x)$, where $x$ is the longitudinal fraction of the hadron momentum carried by the parton. At high energies and forward rapidities $x$ is small and these logarithms need to be resumed. This is accomplished by means of various “small $x$” evolution equations, which essentially are various extensions of the pioneering Balitski-Fadin-Kuraev-Lipatov (BFKL) evolution equation (see e.g. [@Lipatov:1996ts]). In the small $x$ domain the transverse momenta of the partons exchanged between the perturbative and nonperturbative parts are not suppressed comparing to the 