AdipoQ is a novel adipose-specific gene dysregulated in obesity. Researchers identified this gene using mRNA differential display, revealing it encodes a secreted protein with homology to C1q subunits, collagen α1(X), and cerebellin. AdipoQ is specifically expressed in mature adipocytes, not in the stromal-vascular fraction of fat tissue. Its expression increases during adipocyte differentiation and is significantly reduced in obese mice and humans. AdipoQ may function as a signaling molecule in adipose tissue, given its tissue-specific expression and secretion. Adipose tissue is not just a storage site but also secretes signaling molecules that regulate energy homeostasis. AdipoQ's expression is regulated during adipogenesis and is affected by obesity, suggesting a role in adipose tissue physiology. The study highlights the importance of understanding adipose tissue signaling in health and disease. AdipoQ is structurally similar to C1q and may interact with similar receptors, potentially influencing biological responses. The identification of AdipoQ provides new insights into adipose tissue function and may lead to new therapeutic strategies for obesity-related disorders. AdipoQ is identical to Acrp30, a previously identified adipose-specific protein. This study underscores the complexity of adipose tissue biology and the potential for novel molecular tools in understanding adipose tissue function.AdipoQ is a novel adipose-specific gene dysregulated in obesity. Researchers identified this gene using mRNA differential display, revealing it encodes a secreted protein with homology to C1q subunits, collagen α1(X), and cerebellin. AdipoQ is specifically expressed in mature adipocytes, not in the stromal-vascular fraction of fat tissue. Its expression increases during adipocyte differentiation and is significantly reduced in obese mice and humans. AdipoQ may function as a signaling molecule in adipose tissue, given its tissue-specific expression and secretion. Adipose tissue is not just a storage site but also secretes signaling molecules that regulate energy homeostasis. AdipoQ's expression is regulated during adipogenesis and is affected by obesity, suggesting a role in adipose tissue physiology. The study highlights the importance of understanding adipose tissue signaling in health and disease. AdipoQ is structurally similar to C1q and may interact with similar receptors, potentially influencing biological responses. The identification of AdipoQ provides new insights into adipose tissue function and may lead to new therapeutic strategies for obesity-related disorders. AdipoQ is identical to Acrp30, a previously identified adipose-specific protein. This study underscores the complexity of adipose tissue biology and the potential for novel molecular tools in understanding adipose tissue function.