A Western blot analysis showed that CREPT was undetectable in 4T1EXO and 231EXO (Figure S3A), as well as B16EXO (Figure S3B), although Vesiclepedia database (http://www.microvesicles.org) reported the presence of the CREPT protein in small extracellular vesicles from several cancer cell lines. Here, RPRD1B is linked to cancer.