TNFSF13B and infection: Interestingly, the analysis of interactions between expanding immature neutrophils and Follicular B cells (FoBs) also resulted in identification of BAFF signaling as the main communication pathway (Fig. s6a), with infection-derived FoBs downregulating Tnfrsf13b (TACI), despite the upregulation of Tnfsf13b (BAFF) and Tnfsf13 (APRIL) by N1 and N2 neutrophils (Supplementary Fig. s6b).