 Last but not least, Collapse Theories qualify themselves as rival theories of quantum mechanics and one can easily identify some of their physical implications which, in principle, would allow crucial tests discriminating between the two. Getting stringent indications from such tests requires experiments, whose technology has been developed only very recently. Actually, it is just due to remarkable improvements in the field of opto-mechanics and cold atoms, as well as nuclear physics, that specific bounds have already been obtained for the parameters characterizing the theories under investigation; more important, precise families of physical processes in which a violation of the linear nature of the standard formalism might emerge have been clearly identified and are the subject of systematic investigations which might lead, in the end, to relevant discoveries.