Single cell sequencing of cells expressing T cell receptor β (TCRβ) showed gene expression profiles of cytotoxicity and effector-functions together with elevated traits of exhaustion, i.e., Pdcd1 and Tox. PD-1+ CD8 T cells accumulated to high numbers of NASH-HCC mice in the liver with a resident-like T cell character. The gene discussed is PDCD1; the disease is hepatocellular carcinoma.