Cell growth pathways are mediated through protein-glycan interactions including O-glycosylation. Investigation of these growth pathways can be carried out using appropriate inhibitors to identify stage-specific events. We have adopted this approach to study a group of benzyl-O-N-acetyl-D-galactosamine analogues in human colorectal cancer cell lines. Exposure to O-glycan inhibitors resulted in the induction of apoptosis, a block in proliferation, accumulation of intracellular aryl-glycans and changes in related genes as detected by gene array. Colorectal cancer cell lines susceptible to the inhibitors showed growth arrest with all compounds. However, a differential action of each inhibitor was detected in the pattern of genes affected and in the structure of aryl-glycans formed.