Further, TCF-1+ PD-1INT and TCF-1+ CXCR5+ gene signatures in both TIL and circulating T cells have been shown to have predictive prognostic value in human melanoma and lung cancer patients, and in chronic viral disease, highlighting the therapeutic potential of this lineage [81,85,91,92,93,94]. The gene discussed is TCF7; the disease is lung carcinoma.