Though Sec61 and Sec63 have been linked to human diseases as well, a potential function of these proteins as diagnostic or prognostic biomarkers seems unlikely, as all diseases showing SEC61A1 and SEC63 mutations can also be caused by other genetic alterations.80,81,103 In the context of human cancer, the percentage of gastric cancer,82 small-bowel cancer83 and colorectal cancer cases82 showing frameshift mutations of SEC63 as well as the percentage of glioblastoma cases showing a SEC61G amplification and overexpression85 is too low to allow diagnostic conclusions. Here, SEC63 is linked to colorectal cancer.