Precision medicine in autoimmune diseases: fact or fiction.

Much is said about precision medicine, but its real significance and potential are far from certain. Several studies in each of the autoimmune diseases have provided important insights into molecular pathways, but the use of molecular studies, particularly those looking into transcriptome pathways, has seldom approached the possibility of using the data for disease stratification and then for prediction, or for diagnosis. Only the type I IFN signature has been considered for therapeutic purposes, particularly in the case of SLE. This review provides an update on precision medicine, on what can be translated into clinical practice and on what single-cell molecular studies contribute to our knowledge of autoimmune diseases, focusing on a few examples. The main message is that we should try to move from precision medicine of established diseases to preventive medicine in order to predict the development of disease.