Δ9-Tetrahydrocannabinol (THC) inhibits epidermal growth factor (EGF)-induced wound healing in NSCLC cells. Confluent layers of A549 and SW-1573 cells were scratched with sterile tips to form wounds and then were cultured in the presence of EGF+vehicle or EGF+THC (72 h). Phase-contrast images were collected using a light microscope (Nikon). Total wound areas were measured using Scion Image software, and the % wound recolonization was calculated. (a) Illustration of the wound healing experiments described above. (b and c) Quantitative analysis of wound healing shows a significant inhibition of the EGF-induced chemotaxis upon THC treatment of A549 and SW-1573 cells. Data reflect the mean±s.d. Representative experiments (n=2) are shown (**P<0.001; compared to EGF-only stimulated cells).