In the context of cancer, gene expression becomes highly significant because cancer is fundamentally a genetic disease. Abnormal gene expression can lead to the uncontrolled cell division that characterizes cancer. Genes that are commonly altered in cancer include oncogenes and tumor suppressor genes. Oncogenes are genes that, when mutated or overexpressed, drive the proliferation of cancer cells. In contrast, tumor suppressor genes are those that normally prevent cell division and promote cell death, and their loss of function can enable cancer progression.
