MYD88 and primary central nervous system lymphoma: The MYD88 and CD79B gene mutation together leads to the B cell receptor signaling pathway activation to promote the development and progression of PCNSL.335 MYD88 missense mutations result in constitutive activation of the TLR pathway,336 while CD79B alteration activates the BCR pathway.337 Caspase activation and recruitment domain 11(CARD11) mutations activate both pathways downstream,337 while tumor necrosis factor alpha-induced protein 3 (TNFAIP3) alterations can cause pathways to lose inhibition.