Recently high specificity of PDEδ towards K-Ras trafficking to reach plasma membrane rafts to initiate signaling was demonstrated [139, 140], and the same was exploited by designing small molecules such as Deltarasin (Figure 4) and related analogs to block the binding pocket of PDEδ leading to K-Ras mislocalization and downregulated cancer signaling leading to reducing cell proliferation and finally cancer cell death [137, 141]. Here, PDE6D is linked to cancer.