we used these gene-amplified cells , their revertant counterparts ( grown in the absence of the drug after an established gene amplification ) and tumour cells grown in the presence of putrescine to investigate the changes of ornithine decarboxylase gene pattern and simultaneously occurring phenotypic changes , such as tumourigenicity and the expression of cell-surface glycoproteins .
C0007634
cells
C0699040
of cell-surface