MYD88 and primary central nervous system lymphoma: In this regard, the high frequency of MYD88 (36–85% of PCNSL cases) [20,21,41] and CD79B (8–59% of PCNSL cases) [21,23,41] mutations is of note because they foster signaling along the TLR and BCR pathways, respectively (Figure 1 and Figure 2).