CD44 and triple-negative breast carcinoma: However, another HSP90α-involving mechanism was proposed for CSC-like cells in triple-negative breast cancer: HSP90α together with GRP78 interacts with the zinc finger motif-containing C-terminal region of RPDM14, which was associated with cancer cell stemness, whereas the prevention of those HSP90α–RPDM14 interactions by HSP90 inhibitors or GRP78 inhibitors led to a decrease in the CSC-like cell populations (CD24−/CD44+ and SP cells) [80].