We performed a large collaboration with the study group led by Professor Katayama at Saitama Medical University to perform a randomized controlled trial called “Azelnidipine (a calcium (Ca) channel blocker) and Temocapril (an ACE inhibitor) in Hypertensive Patients with Type 2 Diabetes Study (ATTEST) [16]”, which included genetic analysis to evaluate the therapeutic effects of azelnidipine and temocapril. Here, ACE is linked to type 2 diabetes mellitus.