Although the first PDEδ inhibitor, Deltarasin, and the follow-up series of Deltazinones had antiproliferative effects and prevented association of PDEδ with KRas and Rheb, they were designed to target oncogenic Ras hyperactivation on Ras-driven cancer cells (Zimmermann et al., 2013; Papke et al., 2016; Klein et al., 2019). The gene discussed is PDE6D; the disease is cancer.