DUSP1 and breast cancer: So, proteasome inhibitors such as bortezomib, carfilzomib and recently BU-32 (144) have been considered as potential therapeutic agents for breast cancer that is resistant to endocrine therapy, through the inhibition of mitogen-activated protein kinase phosphatase 1 (MKP-1) as well as the inhibition of signaling cascades responsible for hormone independence and anti-endocrine resistance (145).