SNAI1 and breast cancer: Snail overexpression in ARCaP prostate cancer cells increased ERK activity, which was associated with increased cell migration and decreased cell adhesion [23].The present study associates Snail expression and p-ERK with breast cancer progression, as Snail protein and ERK activity was increased in breast cancer patient tissue as well as breast cancer cell lines (MCF-7, T47-D) and triple negative breast cancer cells (MDA-MB-231).