| This is one of the cell-penetrating peptides (CPPs) derived from the human immunodeficient virus (HIV)-1 Tat protein residue 48-60. It has been used to deliver exogenous macromolecules into cells in a non-disruptive way. GRKKRRQRRRPPQ; H - Gly - Arg - Lys - Lys - Arg - Arg - Gln - Arg - Arg - Arg - Pro - Pro - Gln - OH |