Proposed mechanism whereby GNA13 loss promotes lymphomagenesis within the GC niche. In normal circumstances, GC B cells follow the path depicted with green arrows. Mutations in GNA13 lead to disordered migration and impaired apoptosis. Affected cells likely do not require prosurvival signals from T helper (Th) cells to persist. GC persistence may promote the accumulation of additional mutations through ongoing SHM. Over time, accumulation of driver mutations in persistent GC cells may promote lymphoma. FDC, follicular dendritic cell.