The ability of RAC1B to block two tumor-promoting functions of TGF-β, EMT and cell motility in vitro is a significant observation in the light of recent data revealing that RAC1B protein expression was more abundant in a PDAC-derived cell line of low metastatic potential (Colo357) compared with a cell line of high metastatic potential (Panc1) and, even more striking, in PDAC tissues correlated with prolonged patient survival [6]. This evidence concerns the gene TGFB1 and neoplasm.