  Consistency of the previously suggested color-dipole representation of
deep-inelastic scattering (DIS_) and vector-meson production at low x with
DGLAP evolution allows one to predict the exponent of the W^2 dependence of the
saturation scale Lambda_sat^2(W^2) ~ (W^2)^C-2. One finds C_2^theory = 0.27 in
agreement with the model-independent analysis of the experimental data from
HERA on deep-inelastic electron scattering.
