The present invention relates to granulocyte colony stimulating factor
("G-CSF") analog polypeptide compositions, related nucleic acids,
expression constructs, host cells, and processes for recombinant
production of the present G-CSF analogs. The concept detailed herein
involves novel mutants of G-CSF, using single substitutions to amino
acids, which were rationally chosen to affect the cellular trafficking of
G-CSF and/or G-CSFR. In addition, pharmaceutical compositions, and
methods of use are provided.