FCGR2B and cancer: We thank Silvia Bolland (NIAID, NIH) for the H2K-FcγRIIB (Y307→F)-IgH enhancer construct, Jeffrey Ravetch (Rockefeller University) for B6.FcγRIIB deficient mice, Ullrich Hammerling (Sloan Kettering) for the K9.361 hybridoma, Scot Fenn for technical assistance, Carlisle Landel in the Kimmel Cancer Center Transgenic, and Knockout Facility for construction of transgenic mice, and all members of the Manser laboratory for their indirect contributions to this work.