  We discuss the relation between partonic distributions near the phase space
boundary and Wilson loop expectation values calculated along paths partially
lying on the light-cone. Due to additional light-cone singularities,
multiplicative renormalizability for these expectation values is lost.
Nevertheless we establish the renormalization group equation for the light like
Wilson loops and show that it is equivalent to the evolution equation for the
physical distributions. By performing a two-loop calculation we verify these
properties and show that the universal form of the splitting function for large
x originates from the cusp anomalous dimension of Wilson loops.
