  We discuss Drell-Yan production of dileptons at high energies in forward
rapidity region in a hybrid high-energy approach. This approach uses
unintegrated gluon distributions in one proton and collinear quark/antiquark
distributions in the second proton. Corresponding momentum-space formula for
the differential cross sections in high-energy approximation has been derived
and will be presented. The relation to the commonly used dipole approach is
discussed. We conclude and illustrate that some results of the dipole
approaches are too approximate, as far as kinematics is considered, and in fact
cannot be used when comparing with real experimental data. We find that the
dipole formula is valid only in very forward/backward rapidity regions ($|y| >$
5) that cannot be studied experimentally in the moment. We performed
calculations of some differential cross sections for low-mass dilepton
production by the LHCb and ATLAS collaborations. In distinction to most of
dipole approaches, we include all of the four Drell-Yan structure functions,
although the impact of interference structure functions is rather small for the
relevant experimental cuts. We find that both side contributions ($g + q/\bar
q$ and $q/\bar q + g$) have to be included even for the LHCb rapidity coverage
which is in contradiction with what is usually done in the dipole approach. We
present results for different unintegrated gluon distributions from the
literature (some of them include saturation effects). We see no clear hints of
saturation even at small $M_{ll}$ when comparing with the LHCb data.
