The BAFFling function of Syk in B-cell homeostasis.

The TNF receptor family member BAFFR is essential for providing mature B cells with pro-survival signals and has recently been claimed to transduce these, though not exclusively, via a Syk-dependent signaling hub that feeds into ERK/AKT activation. In this issue of The EMBO Journal, Hobeika et al (2015) describe a synergistic prosurvival scenario involving BAFFR and CD19, which remains functional under Syk null conditions and is able to maintain mature B-cell survival. The authors hence propose a BAFFR-/CD19-driven mechanism to act in parallel with homeostatic NF-κB/AKT activation in non-stimulated B cells.