New targets and new drugs: from in silico planning to in vivo testing

The XX century has witnessed the emergence of two pandemics: the "Spanish" H1N1 influenza A in 1918-1919 and AIDS in early 80's. At the beginning of the XXI century, the AIDS pandemic is still far from being under control, let alone be solved, while a novel human influenza pandemic virus already emerged, along with limited but still worrisome outbreaks of "new" viruses such as the avian H5N1 influenza A virus and the SARS coronavirus. Moreover, starting from the second half of the XX century, cancer and cancer-related diseases have become major death causes in the adult population of western countries. In addition to these "novel" diseases, "old" ones like malaria and tuberculosis are still taking an heavy toll in terms of human lives in third-world countries.
While vaccine development efforts are under way, our first, and often only, line of defense against transmissible diseases as well as many types of cancer is represented by chemotherapeutic agents. The emergence of drug-resistant phenotypes in viruses as well as in cancer cells always demands for the development of novel drugs, while the limited safety and efficacy of current chemotherapeutic regimens highlight the need for the identification of novel molecular targets.
When confronted with newly emerging diseases, time is of essence, so the possibility to rapidly identify a suitable target and tailor a selective inhibitor on it, is crucial. Under this respect, advancements in basic science and applied technologies have brought a tremendous increase in our ability to rapidly develop chemotherapeutic agents. This issue will provide relevant examples of such possibilities, taken from a broad range of applications.