Plasma cytokine profiling highlighted soluble CD27 and PD-1 as significantly elevated in ChILI relative to controls on CPI.<h4>Conclusions</h4>We have shown that circulating CD8<sup>+</sup> T cells provide a potential biomarker to distinguish ChILI from DILI and AIH, and highlight different mechanistic pathways between ChILI and other immune-mediated liver injuries. The gene discussed is CD8A; the disease is autoimmune hepatitis.