HSPA5 and breast cancer: Operating with MDA-MB-231 and MCF-7 cells, Conner et al. [28] have revealed that the GRP78 overexpression in the breast cancer cells is associated with an occurrence of CD24-/CD44+ tumor-initiating cells (TICs) and sGRP78+ breast cancer cells, exhibiting the expression of stemness genes, are a subset of TICs.