Previous studies suggested that an increased frequency of CD27+CD45RO-CD8+ T cells at the time of leukapheresis may correlate with sustained remission in patients with chronic lymphocytic leukemia treated with CD19 CART cells (21), in multiple myeloma patients treated with B cell maturation antigen (BCMA)-specific CART cells (22), and very recently in patients with DLBCL (23). Here, CD27 is linked to B-cell chronic lymphocytic leukemia.