Rac1 is reported to play both tumor-promoting role and tumor-suppression role in certain kinds of tumors, which indicates that the function of Rac1 remains controversial and is related to a complex network of tumor regulation (Engers et al., 2001; Malliri et al., 2002; Baugher et al., 2005; Chen et al., 2011; Frances et al., 2015). The gene discussed is RAC1; the disease is neoplasm.