This finding suggests that cases of B-cell lymphomas with loss of CD20 should be screened for the genomic loss of MS4A1. Such screening will help identify patients who need early intensive treatments including stem cell transplants to overcome a CD20-negative relapse of B-cell lymphomas, because genomic deletion of MS4A1 appears to be an irreversible event that leads to the permanent loss of the immunotherapeutic target, and ultimately to reduced survival of the patient. Here, MS4A1 is linked to B-cell non-Hodgkin lymphoma.