RESUMEN
The concept of exosomes has evolved from be considered garbage bags to the demonstration that exosomes could play very interesting roles and functions, from biomarkers detection to the potential of work as drug delivery systems. It has been widely proved that exosomes can contain key molecules important for the tumour development. The current review summarizes the latest investigations developed in the field of predictive exosomal biomarkers. The microRNAs (miRNAs) are the more known molecules due to their amount inside the exosomes and the sensitivity of the techniques available for their study. However, exosomal proteins, RNA and DNA are becoming an interesting and more feasible field of study due to the improvement in the techniques available for their analysis. In the future years, it is hoped that exosomes will become an established member of the liquid biopsies in the clinical practice due to their diagnostic and prognostic properties.