Why is miR-15b-5p included as an internal control?

miR-15b-5p is included in the Yenos assay as an internal control — a built-in quality check that verifies the test ran correctly. Unlike the three cancer biomarkers (miR-21, miR-375, miR-141), miR-15b-5p should NOT change between healthy and cancer populations. Its level remains stable because it is not a cancer-associated miRNA. By measuring miR-15b-5p alongside the cancer markers, the laboratory can confirm that the sample was properly collected, preserved, shipped, and processed, and that the nanopore platform performed correctly during the run. If miR-15b-5p shows an unexpected value, it indicates a technical issue — not a cancer signal — and the test can be flagged for re-run.