Wiktionary
expressome
n. (context genetics English) All the gene expressions in a cell or organism considered as a whole
Wikipedia
Expressome
Expressome refers to the whole set of gene expression in a cell, tissue, organ, organisms, and species.
Expressome is a slightly larger concept than transcriptome. Transcriptome is the set of transcripts, while expressome includes transcripts, proteins and other ligands (how much concentration).