Heavy flavor production off protons and in a nuclear environment

These lectures present an overview of the current status of the QCD based phenomenology for open and hidden heavy flavor production at high energies. A unified description based on the light-cone color-dipole approach is employed in all cases. A good agreement with available data is achieved without fitting to the data to be explained, and nontrivial predictions for future experiments are made. The key phenomena under discussion are: (i) formation of the wave function of a heavy quarkonium; (ii) quantum interference and coherence length effects; (iii) Landau-Pomeranchuk suppression of gluon radiation leading to gluon shadowing and nuclear suppression of heavy flavors; (iv) higher twist shadowing related to the finite size of heavy quark dipoles; (v) higher twist corrections to the leading twist gluon shadowing making it process dependent.