To evaluate whether similar heterogeneity and developmental links are observed among Tph cells in tissues, we evaluated PD-1hi CD4 T cells in the murine model of pristane-induced lupus in C57BL/6 mice, a flexible model of lupus that involves activation of extrafollicular T-B cell interactions and can be induced in multiple strains (33). Here, CD4 is linked to systemic lupus erythematosus.