Stimulating T cells with JCV (LT) Peptide Pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. This peptide pool is a lyophilised mixture of 170 peptides from large T antigen (LT) of JC polyomavirus (JCV), and consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 688 on LT. LT is detectable during JCV latency (Rossi et al.), and in immunocompromised patients with JVC-associated pathologies such as progressive multifocal leukoencephalopathy (PML) (Delbue et al.). In PML, LT has been associated with activating the promoter of survivin, an anti-apoptotic protein (Del Valle et al.). Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development.