Kinguchi S, et al. - In angiotensin-dependent hypertension, researchers assessed the in vivo functional role of renal proximal tubule ATRAP (angiotensin II receptor–associated protein; Agtrap). For the first time using the Cre/loxP system with Pepck-Cre, they successfully generated proximal tubule–specific ATRAP knockout (PT-KO) mice. Using immunohistochemical and laser-capture microdissection analysis, estimation of renal ATRAP expression in PT-KO mice was done. Compared with wild-type mice, a decrease in ATRAP mRNA expression by ≈80% was observed in proximal regions of the nephron in PT-KO mice. Overall, angiotensin-dependent hypertension in vivo was not exacerbated by ATRAP deficiency in proximal tubules. Findings were suggestive of a minor role of renal proximal tubule ATRAP in angiotensin-dependent hypertension in vivo.