Recently, we face the rapid progression of an aging population, and so the importance of preventive medicine is growing. We would all like to pursue a healthy life during old age through effective treatment on the basis of the early detection of diseases. In this situation, we have developed MUSTag (Multiple Simultaneous Tag) assay technology through an innovative modification of the immuno-PCR method for the super-sensitive and multiplex detection of target biomarkers. In MUSTag technology, each different oligo-tag simultaneously detects multiplex protein targets with extremely high-level sensitivity (more than 10 fg(10(-15) g)/ml) in a dose-dependent manner by qRT-PCR (maximum: 3 plexes). Herein we report our recent results of multiple cytokine assays or disease-specific biomarker assays using MUSTag technology, and, further, clinical results from patients with cancer, ischemic brain, or heart attack, who need a prompt and predictive diagnosis for adequate treatment.