Genes for tumor markers are clustered with cellular proto-oncogenes on human chromosomes.

We have analyzed the relative mapping positions of genes for polypeptides expressed abnormally in tumors (tumor markers) and cellular proto-oncogenes and find a remarkable degree of co-mapping of tumor marker genes with oncogenes in the human karyotype. We propose that aberrant expression of marker genes in tumors may be related to their proximity in the human genome to oncogenes expressed during the development of malignancy, and we suggest ways to test this hypothesis of concerted abnormal gene expression in mammalian tumor cells.