RAC1 and neoplasm: Recently, various small‐molecule inhibitors targeting different Rho GEF members have been successfully developed: NSC23766 effectively inhibits tumor metastasis by specifically blocking Tiam1–Rac1 interaction [283]; ZINC69391 and its derivative 1A‐116 exert inhibitory effects by targeting the DH domain of P‐Rex1 [285]; while intervention at the PH domain of Ect2 has been proven to effectively disrupt its binding with RhoA [297] (Table 3).