CD44 and ovarian carcinoma: We have found that the addition of either neutralizing CD44 antibody or HA oligomers (6–10 sugar residues), which interact monovalently with CD44 and competitively block polyvalent interactions between CD44 and endogenous HA, blocked the HA induced chemoresistance in CD44 positive ovarian cancer cell lines but not in the CD44 negative, OVCAR-3 cells.