PDCD1 and systemic lupus erythematosus: In SLE patients treated with low-dose IL-2, there were an increased number of CD4+CD25highCD127low Treg cells and a reduced number of CD4+CXCR5+PD-1+CCR7low Tfh cells, but the number of CXCR3+CCR6-CCR4-CCR7low Th1 cells was not significantly affected (43).