STARD13 and neoplasm: Since RhoGDIs are able to modulate Rho GTPase interaction with Rho guanine nucleotide exchange factor (RhoGEFs) and Rho GTPase-activating proteins (RhoGAPs), RhoGDI2 may activate Rac through the altered regulation of GDP/GTP cycling and then Rac activation may be able to antagonize tumor invasion and metastasis (15).