Peptide growth factors and products of some oncogenes are likely to be active in common regulatory pathways that control the cell cycle. 2. Cell transformation by DNA-mediated transfections with cloned oncogenes is an approach that can provide insight into the mechanisms of both growth factor action and cell cycle regulation. 3. This paper deals with this approach, summarizing and discussing transfection experiments of mouse c-myc and human c-Ha-ras-1 cloned oncogenes into mouse embryo Balb-3T3 cells.
