Final answer:
Protein concentration is regulated by processes like nuclear export, RNA processing, and mRNA stability rather than by DNA replication, which is involved in genome duplication during cell division.
Step-by-step explanation:
Protein concentration within a cell can be regulated at multiple steps in the process from gene to protein, but not all steps in gene expression have a direct role in protein concentration. Steps like nuclear export, RNA processing, and mRNA stability are indeed involved in regulating the levels of protein since they affect the processing and availability of mRNA for translation. However, DNA replication is not a step that regulates protein concentration. DNA replication is the process of creating a new copy of the genome, which is necessary during cell division but does not in itself regulate the levels of protein expressed from the genes.