Somatic hypermutation targeting is influenced by location within the immunoglobulin V region

► We have presented a quantitative model for the frequency of each sequence surounding mutations in B cells. ► This motif explains most of the variance in the mutation frequency. ► Within this motif, C mutations to T are more frequent than C to G, which are more frequent than C to A. ► Beyond this motif, a position specific effect explains a part of the mutation frequency.