RAP1A and cancer: It has been shown that Rap1 activation by different Rap1 regulators, such as Rap1 guanine exchange factors (GEFs) or GTPase-activator proteins (GAPs), can either promote or inhibit cell motility and, moreover, to promote or inhibit metastasis in different cancer models26, 34, 35, 36, 37, 38, 39.