AGTRAP (angiotensin II receptor-associated protein) is a 22 kDa cytoplasmic protein that functions as a negative regulator of angiotensin II type 1 receptor (AT1R) signaling 1. AGTRAP binds to the carboxyl-terminal domain of AT1R and suppresses Ang II-mediated pathological responses by promoting AT1R internalization and receptor desensitization 2. The protein interacts with RACK1 to recruit signaling complexes that modulate AT1R function 1. AGTRAP is broadly expressed in kidney, heart, pancreas, thyroid, and adipose tissues 13. In cardiovascular pathophysiology, tissue-specific AGTRAP expression balances AT1R signaling; activation of AGTRAP in transgenic models inhibited inflammatory vascular remodeling and cardiac hypertrophy 2. AGTRAP protects against metabolic dysfunction associated with visceral obesity, insulin resistance, and dyslipidemia 3. Age-associated AGTRAP downregulation in vascular smooth muscle cells, mediated by miR-34a upregulation, enhances pro-inflammatory Ang II signaling during aging 4. AGTRAP FAM114A1 interactions regulate cardiac fibroblast activation and pathological remodeling in heart failure 5. Clinically, elevated AGTRAP expression correlates with poor prognosis in hepatocellular carcinoma and glioma and associates with immune infiltration and T-cell exhaustion 67, suggesting potential diagnostic and immunotherapy response prediction applications.