Osteopontin (OPN), a multifunctional protein present in blood and other bodily fluids, has been recognized as a potentially valuable biomarker for diagnosis and prognosis of cancer[272, 273, 274] and nonmalignant diseases.[275, 276, 277] A simple, label‐free electrochemical aptasensor for was developed by functionalizing screen‐printed gold electrodes with an OPN‐specific aptamer, and its performance was evaluated using square wave voltammetry measurements in serum to achieve an LOD of 1.4 nM.[278] Toward the development of a point‐of‐care test strip, Pereira et al. The gene discussed is SPP1; the disease is cancer.