To determine whether Rac/Cdc42 inhibitors affect the viability of macrophages at the therapeutic window, i.e. IC50 of 1.1 μM for EHop-016 and IC50 of 100 nM for MBQ-167 in breast cancer cells (25, 26), we determined cell viability as measured by an MTT assay on RAW264.7 and THP-1 cell lines. This evidence concerns the gene CDC42 and breast cancer.