CD44 and breast carcinoma: These results are consistent with previous reports in malignant colon, prostate, and breast carcinoma cells, in which HA-CD44 interaction activated multiple RTKs including EGFR as well as assembly of lipid-raft-integrated signaling complexes containing activated RTKs, CD44, ezrin, PI3-kinase (PI3K) and the chaperone molecules HSP90 and CDC37 [31].