In line with the effect of forskolin on cAMP increase, PDE Inhibitors, which include theophylline, IBMX (both are nonselective PDE inhibitors), ibudilast (a PDE4 selective inhibitor), and rolipram, can induce YAP phosphorylation by restricting cAMP breakdown [153], suggesting the PDE inhibitors may be useful in the treatment of cancer types driven by YAP oncogenic activity (Figure 2 and Table 2). Here, YAP1 is linked to cancer.