CD44 and posterior cortical atrophy: Cluster of differentiation 44 (CD44) is a transmembrane receptor that is known to have significant roles in cell‐cell interactions, cell adhesion, and migration.27 CD44 signaling via extracellular matrix ligands such as hyaluronic acid, osteopontin, collagens, and matrix metalloproteinases has been shown to increase the metastatic potential of cancer cells.28 Moreover, CD44 has also been recognized as a marker of CSCs in breast and PCa.28, 29