KRAS and pancreatic ductal adenocarcinoma: Deltarasin is the first proven benzimidazole inhibitor targeting the farnesyl-binding site of PDE6δ with KD = 7.6 ± 1.3 nM.371 In KRAS-driven human pancreatic ductal adenocarcinoma cells (hPDACs), Deltarasin induces decreased membrane localization of KRAS, inhibits downstream MAPK signaling transduction, and significantly inhibits tumor cell growth both in vitro and in vivo.