KRT18, as one of the most abundant keratins in epithelial and endothelial cells, was reported to be aberrantly expressed in many malignancies and extensively regarded as a diagnostic and prognostic marker in cancers, including non–small cell lung cancer (Zhang et al., 2016), GC (Bilici, 2015; Nagel et al., 2018), hepatocellular cancer (Golob-Schwarzl et al., 2019), breast cancer (Bozza et al., 2018), and colorectal cancer (Zhang et al., 2019a). Here, KRT18 is linked to breast cancer.