The present invention is directed to the field of immunotherapy. Specifically, the invention provides compositions and methods for improved T cell modulation ex vivo and in vivo and for the treatment of cancer and other pathologies. More specifically, embodiments of the invention are directed to the use of soluble NTB-A polypeptides or agonists thereof for the treatment of cancer patients, for preventing and treating cytopenia in susceptible patients, and for the ex vivo preparation of improved cell compositions.
