The intelligence of the natural human immune response can be exploited to recognize antigenic targets useful in oncology. A component of this response, pritumumab, is a natural IgG1 kappa antibody and was obtained through traditional hybridoma procedures from a regional draining lymph node of a patient with cervical carcinoma. The antigen recognized by pritumumab is an altered form of vimentin, called ecto-domain vimentin (EDV), and is expressed on the surface of cancer cells. Phase II clinical trials with brain cancer response rates were between 25% and 30% suggesting pritumumab has some clinical benefit and is suitable for further development as an anticancer therapeutic.