The present invention relates to peptides which home to cells, e.g. heart cells, with high selectivity and which can be useful in the form of compositions. Such compositions can be used, e.g., for selectively targeting a systemically administered therapeutic agent or imaging agent to a cell or tissue in a subject. The present invention further relates to methods of using the compositions for imaging, e.g. PET imaging, and targeting cells, e.g. for delivering a therapeutic agent to one or more target cells in a subject.
