MMP9 and cancer: In the clinical field, e-PADs have been utilized for the determination of a wide variety of biomolecules including miRNAs, hormones (17β-estradiol, FSH), viruses (HPV, HIV), proteomic biomarkers of relevance in cancer and cardiovascular diseases (CRP, BNP, IFN-γ, CA125, cTnI, AFP, BChE activity, MMP9, and CEA), and other clinically relevant analytes (3-NT, glutathione, glucose, H2O2, serotonin, L-Tyr, Phe, acetylcholine and Cl−).