Humoral immune memory is carried by two types of cells, memory B cells (MBCs) and long-lived plasma cells. These cells are mostly high-affinity GC emigrants, but how their fates are determined in a manner that is coupled with GC experience and affinity maturation is not yet clear. We have dedicated efforts in characterizing early MBC precursor within GCs, and identified IL-9 as the Tfh-derived cytokine important for their generation. We are currently working on elucidating more factors controlling MBC development and function. In another line of work, we have combined genetic mouse models and the single-cell sequencing technique to fully characterize the transcriptomic features of murine long-lived plasma cells, which should help pave the way for better understanding of the pathways governing their development, maintenance and function.