FOLR1 and cancer: Rapid, low-cost, practical, disposable electrochemical panel immunosensor systems were developed for the individual and simultaneous determination of anterior gradient-2 protein (AGR2), folate receptor alpha (FOLR1), glycodelin (GLY), and soluble mesothelin-associated protein (SMRP), which are significantly increased in physiological fluids, particularly in ovarian cancer, and are potential biomarkers in the diagnosis of specific cancer types.