CD27 and systemic lupus erythematosus: Human peripheral blood γδT cells can be classified according to their expression of CD27 and CD45 as follows: naive (CD27 + CD45 +), effector memory (CD27+CD45-), central memory (CD27+CD45-), and terminally differentiated (CD27-CD45+), patients with SLE have more CD27+CD45-γδT cells in their peripheral blood and fewer Foxp3+γδTreg cells that express Foxp3 compared to healthy controls, as well as a substantial increase in Vδ1 cells after glucocorticoid and cyclophosphamide treatment (99).