The one on the bottom because the one at the top is at a complete stop and is not growing.
PROTO-ONCOGENES are corresponding normal cellular genes to an oncogene that is responsible for normal cell growth and division.
An oncogene refers to a gene that is capable of causing cancer due to damage to the DNA molecule either by virus or other DNA damaging agents. A proto oncogene is the normal version of the gene while an oncogene is the abnormal version of the concerned gene.