The need to early predict the possible failure of a drug candidate is becoming an absolute requirement in the drug discovery process. For this reason, from the initial phases of lead development, great attention is paid to the ADMET characteristics of the compounds. In this context, the recent discovery that hitting some well-identified macromolecular targets can induce undesired side effects has led drug designers to apply some classical in silico technologies to the goal of avoiding the interaction of lead candidates with such antitargets.: