TPH1 and systemic lupus erythematosus: This pattern of shared Tph/Tfh clones in C5 but not in C3 was consistent across the 3 SLE patients (Figure 3D, E, Extended Data Figure 1G), indicating that cells with a B cell-helper signature, and not CTL, account for the clonal overlap in TCRs of bulk CXCR5− PD-1hi and CXCR5+ PD-1hi pools.