In the case of PDE4, ligands that recruit inhibitor of the apoptosis protein (IAP) E3 ligases were conjugated to an active‐site directed PDE4 inhibitor (piclamilast analogue developed for dry eye syndrome [35]) via a linker in order to construct a PDE4 SNIPER (specific and nongenetic IAP‐dependent protein erasers) [36]. The gene discussed is PDE4A; the disease is dry eye syndrome.