To further confirm that the two activation states of CD44 are differentially located, we assessed CD44 expression and fl-HA binding activity on four breast cancer cell lines (MDA-MB-231, MDA-MB-468, BT-549, and Hs578T) and four normal cell lines (PBMCs, NIH3T3, CV-1, and NFs). The gene discussed is CD44; the disease is breast cancer.