B cells are a crucial part of the vertebrate adaptive immune system and almost all the vaccines being used today rely on invoking B cell responses to confer protection against diseases. Therefore, it is of utmost importance to understand the biology of these cells. After being activated by antigenic and co-stimulatory signals, such as from T cells, naïve B cells either become memory B cells or plasma cells. The exact decision-making process that directs these divergent cell fates still nee...