enhancers in cell-type-specific signatures
Enhancer is a just a term for a regulatory region distant from a gene that contains specific sites where transcription factors bind. As it happens, a single enhancer can contain DNA binding sites for multiple transcription factors. 

For example, an enhancer called TESCO, which regulates a gene called SOX9 (involved in sex determination) has binding sites for many different proteins (confirmed or putative): SRY, SF1, SOX9, ESR1, FOXL2 and likely many more that I haven't heard of. This allows complex regulation of SOX9 through protein-protein interactions.