There was a trend for DON reducing the high frequency of W.Yaa effector memory T cells (CD4+CD44+CD62L– Tem), leading to a significantly decreased Tem/CD4+CD44–CD62L+ naive T (Tn) cell ratio, which is typically elevated in lupus-prone mice (Figure 1, H and I). Here, CD4 is linked to systemic lupus erythematosus.