To investigate whether ROS generation leads to LPA-induced activation of the PI3K/PAK1/ERK signaling pathway and cell migration in cultured breast cancer cells, N-acetyl-L-cysteine (NAC), a known scavenger of ROS, was used and its effect on LPA-induced PI3K/PAK1/ERK activation was examined. The gene discussed is PAK1; the disease is breast carcinoma.