As shown in Fig. 2, the amino acid differences identified are positioned in the CD20 cytoplasmic and transmembrane portions (L198V, A201T and G273E) and importantly in the two extracellular loops (C77Y, L147F, I159M) that are exposed and are potential epitopes of therapeutic and diagnostic antibodies for B-cell lymphoma. This evidence concerns the gene MS4A1 and B-cell non-Hodgkin lymphoma.