The AB toxins are two-component protein complexes secreted by a number of pathogenic bacteria, though there is a pore-forming AB toxin found in the eggs of a snail.

[1] They can be classified as Type III toxins because they interfere with internal cell function.

[4] T The two-phase mechanism of action of AB toxins is of particular interest in cancer therapy research.

The general idea is to modify the B component of existing toxins to selectively bind to malignant cells.

This approach combines results from cancer immunotherapy with the high toxicity of AB toxins, giving raise to a new class of chimeric protein drugs, called immunotoxins.