TAT (47-57) peptide, also known as HIV-1 TAT protein, is the most characterized fragment of the HIV transactivator protein (TAT). TAT (47-57) peptide was show to be a cell-penetrating peptide (CPP). TAT (47-57) is an arginine-rich peptide which directly penetrates plasma membrane and stabilized DNA. TAT (47-57) has the ability to translocate the plasma membrane and facilitate the delivery of various cargoes such as protein, peptide, antibodies, and liposomes. It represents an important tool to increase the biodistribution of drugs.