ERBB2 and B-cell chronic lymphocytic leukemia: Similarly, a CLL-1xCD3 bispecific with weak CD3 binding gave reduced systemic cytokine response compared to a strong CD3 binder [27], and both in vitro and in CD3-humanized mice, a HER2-targeted CD3 bispecific with strong CD3 binding induced greater cytokine production than one with weaker CD3 binding, despite comparable in vivo antitumor activity [28].