The mortality rate in cancer patients demands novel therapy. One of the novel approaches developed in recent decades includes immunotoxins. Cancer cells frequently have specific growth factor receptors/antigens overexpressed on their surface; this is the principle of selective targeting of immunotoxins. Ligands recognizing these receptors and antigens can be conjugated to modified toxins. Continuous efforts are being made (i) to investigate molecules exclusively expressed on cancer cells, (ii) to improve the specificity and efficacy of these immunotoxins, (iii) to eliminate side effects (iv) to decrease immunogenicity and (v) to improve pharmacokinetics and ensure better drug delivery. © 2008 Elsevier Ltd. All rights reserved.