An activating missense mutation (L265P) changing leucine to proline at position 265 in MYD88 has been identified as a driver mutation that promotes B-cell growth and survival in several B-cell NHLs including the ABC subtype of diffuse large B cell lymphoma (DLBCL), Waldenström’s macroglobulinemia/lymphoplasmacytic lymphoma, primary central nervous system lymphoma (PCNSL), cutaneous DLBCL leg type, and testicular DLBCL (22–26). This evidence concerns the gene MYD88 and primary central nervous system lymphoma.