Synuclein α, β and γ are proteins usually found in neurodegenerative diseases. However, interestingly synucleins are expressed in cancer cells of several organs including ovary, mammary gland and colon. By immunocytochemistry using specific antibodies to γ synuclein (SNCG), we examined the distribution of this protein in poorly differentiated, compared to highly differentiated colon cancer cells. In poorly differentiated cancer cells tumors were very frequently stained intensely with antibodies to SNGG, suggesting high expression of this protein. In contrast, in highly differentiated cells, there was no labeling. Labeled cells could be found only at the edges or in between the lobules of the differentiated tumor cells. However, in moderately differentiated tumors, a weak cytoplasmic staining of SNCG was evident. Interestingly in cancer patients (stage II-IV) both poorly and highly differentiated tumor cells were often present in the same patient. Labeled cancer cells with SNCG were evident also in lymph nodes, around the wall of blood vessels and in fat tissue, where only poorly differentiated cancer cells were exclusively present. Since cancer cells with poor differentiation are believed to be aggressive with metastases formation it is suggested that SNCG can serve as a marker for the potential of the tumor cell for the rapid spreading and metastazing of the non-differentiated tumors.