TNFSF13 and B-cell chronic lymphocytic leukemia: It has been published that APRIL is able to induce survival in plasma cells,4 yet no survival effects was found for other developmental stages.4 Similarly, APRIL contributes to naive B cell proliferation, but this was not found in other B cell maturation phases.5 With respect to CLL cells, the effects of APRIL might overlap with its effects on precursor cell from which the CLL cell is derived.