Cellular oncogenes and human carcinogenesis.

Experimental studies over the past decade have identified 30 or so cellular genes as potential oncogenes. The genetic events that lead to cellular oncogene activation may result in the excessive or inappropriate expression of the gene, or the expression of an aberrant gene product. Although the involvement of these putative cellular oncogenes in human oncogenesis has not been proven, the accumulation of considerable experimental evidence strongly implicates some role of these genes in the malignant process. The inactivation of certain genetic loci (suppressor genes) may also contribute to tumor progression.