KL and breast cancer: Several strategies have been developed to deliver (BRBP1-TAT-KLA)/enhance the activity (HPRP-A1) of the pro-apoptotic KLA peptide (disrupts the mitochondrial membrane) to exert an anti-BC effect (apoptosis in MCF-7 BC cells, reduction in tumor weight/volume, metastasis decrease), and importantly, normal tissues were not affected [275,276,277].