Table 2.

Lessons Learned in Preclinical Models.

Effect	Contributing Evidence	Murine Models	Toxins	Ref. #
Anti-tumor effect of immunotoxins is partially mediated by the immune system	Depletion of CD8+ cells with or without depletion of CD4+ cells reduces survival	Malignant astrocytoma, Melanoma	MR1-1, IL13-PE38	[51,52]
Immunotoxins render tumors more sensitive to immune checkpoint inhibitors	Increased survival and number of tumor infiltrating CD8+ cells demonstrated in the combination treated mice.	Breast cancer, Mesothelioma, Glioma	SS1P, LMB-100, D2C7	[53,54,57]
Immunotoxins induce markers of immunogenic cell death	Increased ATP secretion and calreticulin surface expression.	Mesothelioma	SS1P, LMB-100	[54]