Our proximity ligation assay showed significantly fewer BK–RyR coupling sites with a sub-40-nm spatial separation in VSMCs from hypertensive mice compared with normotensive mice, implying a degree of physical separation in BPH/2 mice sufficient to reduce [Ca2+] to less than 10 μM and impair BK channel activation. The gene discussed is KCNMA1; the disease is benign prostatic hyperplasia.