Tan et al. utilized TAT-derived peptides (P1, P2, P3) coupled to an anti-HER2 peptide mimetic (AHNP) and STAT3 inhibiting peptide (P1/P2/P3-AHNP-STAT3) to enhance the TAT-dependent internalization and delivery of the therapeutic peptide into different HER2-overexpressing breast cancer cells including MDA-MB-435, SKBr3, and BT-474. Here, ERBB2 is linked to breast carcinoma.