TRPM7 and breast cancer: Viability, migration and TRPM7 function on BC cell lines were tested.Lidocaine at 1 and 3 mM (24 h) significantly suppresses the viability of BC cell lines with exception of MCF-7, and with greater effects on AU565, T47D and BT-20 cell lines. Lidocaine at 0.3 mM (24 h) only inhibited the viability of AU565 cell line.Lidocaine at 1 and 3 mM (24 h) suppressed cell migration in all the cell lines but at 0.3 mM the migration is only supressed on MDA-MB-231, AU565, and BT474.TRPM7 plays a role in mediating lidocaine’s effects on viability and migration of MDA-MB-231, AU565, T47D and MDA-MB-468.