ARHGEF2 and neoplasm: RASSF1A depletion underlies tumor initiation and progression [18] since inducing epithelial to mesenchymal transition (EMT) in human bronchial cell lines with a pro-metastatic phenotype sustained by both i) guanine nucleotide exchange factor 1 (GEF-H1) inactivation and subsequent RhoB (a putative anti-metastatic small GTPase) inactivation and ii) nuclear accumulation of the active form of the Hippo pathway transcriptional cofactor YAP (Yes-associated protein) [25].