Finally, after validating the use of the SRVB/A assay for NES identification on the “XPO1/CRM1-cancer exportome” protein group, we used it to search for functional NES motifs within the recently uncovered “micropeptidome”, a potentially vast and still largely unexplored group of small proteins shorter than 100 amino acids in length [21,32]. This evidence concerns the gene XPO1 and cancer.