XCL1 is a tissue residency–associated chemokine. (A) Venn diagram of differentially expressed genes derived from bulk RNA-seq data (data from Milner et al. [2020]; Miller et al. [2019]; Nath et al. [2019]). (B) scRNA-seq displaying Xcl1 expression in CD8⁺ isolated from spleen and IEL D32 following LCMV-Arm infection (data from Kurd et al. [2020]). (C) Expression of XCL1 and XCL2 in human CD8⁺ T cells sorted from healthy donor PBMC, rectum, and ileum (data from Boland et al. [2020]). (D) Quantification of P14 (IEL and LP) and XCR1⁺ DC (LP) during LCMV-Arm. (E) Confocal microscopy (left) of murine SI following P14 adoptive transfer and LCMV-Arm (D8 and D35 after infection). Colors are indicated, and scale bar is shown. P values shown, paired two-tailed t test (C), and two-way ANOVA (D). Data are pooled from at least two independent replicates, n = 6 per group (D and E).