In a recent publication [247], Conner et al. described that the GRP78 expression on the surface of breast cancer cells is clearly associated with their reprogramming toward the stem phenotype with high metastatic potential: The tumor-initiating CD24−/CD44+ cells, whose surface was “marked” by GRP78, exhibited an increased propensity to metastasis formation in vivo. Here, CD44 is linked to breast carcinoma.