CD44 and cancer: Interestingly, we found that SKOV-3 cells, which produced the highest HA levels, were most resistant to CBP and expressed the highest levels of ABCC1 and ABCC3. CD44 co-localizes in the plasma membrane of cancer cells with ABCB1 and ABCG2, and HA antagonists rapidly induce internalization of these transporters and CD44 to make them ineffective [34,52,54].