AhR is constitutively expressed in CD49a⁺TRAIL⁺DX5⁻ liver-resident NK cells. (A) Representative flow cytometry profile of CD49a and DX5 expression on liver NK (NK1.1⁺CD3⁻) cells. (B) Expression of TRAIL (left) and CXCR6 (middle) on CD49a⁺ liver NK cells. (Right) CXCR6 mRNA expression in FACS-sorted CD49a⁻DX5⁺ and CD49a⁺DX5⁻ liver NK cells, normalized to HPRT and shown relative to CD49a⁺DX5⁻ liver NK cells. (C) CD49a⁻DX5⁺ or CD49a⁺DX5⁻ NK cells were sorted from the BM, spleen, and liver of WT mice. AhR mRNA expression was assessed by quantitative RT-PCR, normalized to HPRT, and shown relative to BM NK cells (left) or CD49a⁻DX5⁺ liver NK cells (right). (D, left) Representative flow cytometry profile of CD49a and AhR expression in liver NK cells. (Right) Mean fluorescent intensity (MFI)–isotype control of AhR staining in CD49a⁻DX5⁺ versus CD49a⁺DX5⁻ liver NK cells. (E, left) Representative flow cytometry profile of TRAIL and AhR expression in liver NK cells. (Right) AhR mRNA expression in FACS-sorted TRAIL⁻ and TRAIL⁺ liver NK cells, normalized to HPRT and shown relative to relative to TRAIL⁻ liver NK cells. Dot plots are from at least two independent experiments, and n = 3–8 mice per group. All contour plots are representative of at least three independent experiments. Data are shown as mean ± SEM. **, P < 0.01; ***, P < 0.001 (paired Student’s t test).