HSPB1 and cancer: Studies of in vivo metastasization revealed that Hsp27 is overexpressed in the aggressive forms of human BC, with a 2.57-fold increase over the median in cancers that are positive for lymph node invasion and a 2.95-fold increase over the median in the metastatic ones, pointing to Hsp27 as a potential therapeutic target for negative chaperonotherapy in BC with bone metastases [49].