PDE3A and depressive symptom measurement: Ten years ago, Sun et al. observed that PDE3A was the primary subtype of PDE3 expressed in platelets.[9] As essential regulators of cyclic nucleotide signaling with diverse physiological functions, including inhibition of platelet aggregation, PDE3A has become recognized as an important drug target for the treatment of various diseases, such as heart failure, depression, asthma, inflammation and erectile dysfunction.[4,10–12]