HSPA1A and neoplasm: In order to further confirm the role of Hsp70 implicated in regulating BCSCs, compound 1, compound 6, and the isolated stable Hsp70 knockdown clone (shHsp70 #755) of MDA-MB-231 cells were used to investigate the in vivo efficacy of Hsp70 inhibition in suppressing tumorigenesis and xenograft tumor growth, respectively.