Similarly, activation of epidermal growth factor receptor (EGFR) leads to an expansion of CD44+/CD24− populations in TNBC (which is heavily enriched in basal-like breast cancer) in a mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) dependent manner (Wise and Zolkiewska, 2017). Here, CD44 is linked to breast cancer.