The article, written by Ignacio Melero and Sandra Hervas-Stubbs, together with other scientists from the United States and Great Britain, addresses the use of a new pharmaceutical family with practical applications in cancer and chronic viral illnesses. Specifically, the article discusses using monoclonal antibodies in order to stimulate the immune system. In this therapy the antibodies are directed to the immune system cells in order to provoke a stronger reaction against cancer. This has the advantage of exploiting a mechanism with an action distinct from the other strategies currently being used to treat cancer, and is capable of interacting with the current treatments so as to make both forms of treatment more powerful. Currently this treatment is being tested in patients with melanoma, kidney and ovarian cancer because there are more ways of measuring the response of the immune system, but he expects to be able to expand this to include other forms of cancer. The first cancer-fighting agent of this kind, anti-CTLA-4, began to be tested in patients in 1999. In melanoma treatment, between 15 and 20% of clinical objectives have been reached (reduction or disappearance of the tumor), which the researchers see as a positive sign to continue with the research. Currently, the researchers study its benefits in cancer survivors through two clinical tests in the third phase. In two years we will test its use as the sole means of treatment, and we will need more time in order to know if its effects in treatment combinations are as positive as the results on test animals predict. Aside from this, there are another four members of this monoclonal antibiotic family, which stimulate the immune system, currently being developed. Their use in patients began a year and a half ago, and to date no conclusions as to their effectiveness has been published.