Second-generation PDE6δ inhibitors, which bind PDE6δ more tightly via extra hydrogen bonds, have demonstrated greater potency for blocking the growth of K-Ras–dependent but not K-Ras–independent pancreatic cancer cells (Papke et al., 2016; Martin-Gago et al., 2017). The gene discussed is KRAS; the disease is familial pancreatic carcinoma.