Stimulating T cells with CMV (IE-1) peptide pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. CMV (IE-1) peptide pool is a lyophilised mixture of 120 peptides from the immediate early protein IE1 (IE1) of human cytomegalovirus (CMV; strain AD169), and consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 491 on IE1. CMV IE1 is a transcriptional transactivator and autoregulator (Cherrington and Mocarski). Studies show that IE1 promotes viral transcription by antagonizing histone deacetylation (Nevels et al.) and, along with IE2, may contribute to the survival of CMV-infected cells by blocking tumor necrosis factor alpha (TNF-α)-induced apoptosis (Zhu et al.). Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development.