Tat-peptide 168-189, a cell-permeable, Tat-labeled fusion peptide derived from residues 168-189 of rat G3BP1, features the HIV Tat sequence at its least conserved terminus to enhance cellular uptake. It serves as the negative control for Tat-peptide 168-189 TFA, which promotes axon growth and neurite proliferation [1].

Tat-peptide 168-189 TFA at concentrations of 10 μM and 20 μM administered for 24 hours enhanced axonal length in isolated DRG cultures by 10 μM and in iMotor neurons by 20 μM [1]. Additionally, a concentration of 10 μM of Tat-peptide 168-189 TFA applied for 3 days increased the total number of axons extending from each neuron [1].