We then correlated CXCR6 with Treg cell markers (CD4, FOXP3, CD25 and CD39), CD8 T cell markers (CD8A, GZMB, TIM3 and PD1) and NK cell markers (CD160, NKG7 and GNLY) in the HCC dataset, all of which demonstrated high coefficients and statistical significance (Additional file 1: Figures S8A–L). The gene discussed is PDCD1; the disease is hepatocellular carcinoma.