This FOA issued by the National Institute on Aging (NIA), National Institutes of Health, encourages grant applications from institutions/organizations that propose to develop research on single cell biology to enhance the understanding of the mechanisms of normal aging and of age-related diseases. Applications using -omics technologies, imaging, optofluidic platforms, mass spectroscopy, whole genome sequencing, and other tools and technologies at the single cell level are encouraged since it is expected that the single cell approach will improve the determination of unique and biologically significant properties of tissues and organs during the aging process.