  We present a detailed description of the Q^2 and x dependence of the
structure functions F2 and FL as extracted from the Deep Inelastic Scattering
data at HERA in the small Bjorken x region. Making use of a
collinearly-improved BFKL equation at next-to-leading order and a treatment of
the running of the coupling using non-Abelian physical renormalization together
with the BLM scale choice allows us to reach low values of Q^2. We also provide
some predictions for future lepton-hadron colliders.
