Studies from two cohorts in which mRNA expression of circulating tumor cells (CTCs) from metastatic breast cancer patients were analyzed found that high expression of KRT16 is associated with a significantly shorter relapse‐free survival, with median values of 28 versus 17.5 months in one cohort and median values of 23 versus 14.8 months in another cohort for high versus low KRT16 expression, respectively.[9]. Here, KRT16 is linked to breast cancer.