PDCD6IP and cancer: Other exosomal proteins already involved in different cancers have been identified as prognostic biomarkers for CRC, including ALIX (ALG 2-interacting protein X), HSP70, CEA, ribosomal protein L13a (RPL13A), hydroxymethylbilane synthase (HMBS), TATA box binding protein (TBP), ATP-binding cassette transporter G1 (ABCG1), copine III (CPNE3), Np73, and Wnt [52].