Traditional aptasensor designs for CRC biomarkers (e.g., TIMP-1, IL-6, MMP-9, TNF-α, CRP, and CEA) rely on either sandwich or direct assay formats (Table 2 summarizes their analytical performance, including limit of detection, selectivity, detection time, and sample matrix; Figure 3). The gene discussed is MMP9; the disease is colorectal carcinoma.