  The HERA data on the proton structure function, $F_2(x,Q^2)$, at very small
$x$ and $Q^2$ show the dramatic departure of the logarithmic slope, $\partial
F_2/\partial\log Q^2$, from theoretical predictions based on the DGLAP
evolution. We show that the running BFKL approach provides the quantitative
explanation for the observed $x$ and/or $Q^2$ -dependence of $\partial
F_2/\partial\log Q^2$.
