HSPB1 and breast neoplasm: Zhang D. et al. reported that Hsp27 is specifically upregulated in HER2-positive breast tumors [117], and different authors found that the upregulation of Hsp27 in BC cells reduces trastuzumab sensitivity by increasing HER2 protein stability [118] and reduces doxorubicin susceptibility by inhibiting the apoptotic cascade [119].