CD3E and primary cutaneous T-cell non-Hodgkin lymphoma: The limited efficacy of immunotoxins has been attributed to several potential factors, including pre-existing antibodies or immunogenicity against CD3e-ITs, the lower levels of CD3e or insensitivity of lymphoma cells in advanced CTCL, the lack of penetration of the immunotoxins into target cell sites, and protective tumor microenvironment (9–13).