Our team has been interested in finding cell lines and tissues where the probability of detection of MPs is higher. Several tools have been developed based on transcript profiles and have been described in several C-HPP JPR Special Issues. We are also using deep MS strategies to characterize rare clinical samples and the resulting datasets are carefully inspected for MPs and uPE1 proteins. Functional annotation of proteins and definition of their role in physiological and pathological environments is our priority. In this direction, we have developed UPEFinder (https://upefinder.proteored.org) for functional annotation of uPE1 proteins (González-Gomáriz J, JPR HPP special issue, 2020).