The CD8+ T cells from the brains of lupus-prone mice exhibited substantial CD69 (Fig. 2a,b) and PD-1 upregulation (Fig. 2c,d) and CD122 downregulation (Fig. 2c,d) relative to peripheral CD8+ T cells from the same mice, indicative of a Trm cell phenotype. Here, CD69 is linked to systemic lupus erythematosus.