The Inventors herein demonstrate that CD39 is a relevant therapeutic target in B-cell
lymphoma, in particular Follicular Lymphoma (FL), Diffuse Large B-Cell Lymphoma (DLBCL) and Mantle Cell Lymphoma (MCL). They also demonstrate that CD39 potentiate
anti-CD20 monoclonal antibody therapy and/or anti-PD1 monoclonal antibody therapy, and that ENTPD1 overexpression is correlated with poor prognosis in FL patients. Accordingly, the present invention relates to a method of treating a B-cell lymphoma in a subject in need thereof comprising administering to the subject a therapeutically effective amount of a CD39 inhibitor.