There are typical recurrent mutations primarily affecting MYD88L265P and CD79B, placing PCNSL in alignment with the MCD (MYD88/CD79B-mutated) lymphoma molecular subtype of DLBCL which is also characterized by poor prognosis and extra-nodal involvement, especially in immune-privileged sites [8,9]. The gene discussed is CD79B; the disease is primary central nervous system lymphoma.