For instance, GPCRs (e.g., GPR78 [22,23]) could interact with Rho GTPase (e.g., RhoA and Rac1) by coupling with the Gαq signalling pathway which is involved in cell migration and invasion [24,25,26].GPR78 knockouts significantly suppressed the cell migration in metastatic lung cancer cell linesbecause it affected the cell motility through the activation of Gαq-RhoA/Rac1 pathway thereby notifying its role in cancer metastasis [23]. Here, RAC1 is linked to cancer.