TBX21 directly upregulates expression of the chemokine receptor CXCR3 in T helper 1 cells (Th1 cells) (inferred from mouse homologs in Szabo et al. 2000, Lord et al. 2005, Zhu et al. 2012). T-bet binds to the 5′ enhancer of the Cxcr3, and without T-bet, H3K4me1 modification is reduced around this binding site (Zhu et al. 2012). Human Th1 cells preferentially express CXCR3 and CCR5 chemokine receptors (Bonecchi et al. 1998). CXCR3 binds three chemokines that are induced by type I interferons: CXCL9 (MIG), CXCL10 (IP‑10), and CXCL11 (I‑TAC) (reviewed in Chu et al. 2023, Rubinstein et al. 2024) to induce the migration of Th1 cells into inflammatory sites (reviewed in Groom and Luster 2011, Zhang et al. 2014).