The study investigates the role of C/EBPα and PPARγ in adipogenesis, a process where precursor cells differentiate into fat cells. Both proteins are critical transcription factors, but their precise roles have been unclear due to their positive feedback loop regulation. The authors created an immortalized line of fibroblasts lacking PPARγ to test whether C/EBPα can promote adipogenesis independently of PPARγ. They found that C/EBPα alone is insufficient to induce adipogenesis in the absence of PPARγ, suggesting that these factors participate in a single pathway of fat cell development with PPARγ being the proximal effector. This finding supports the idea that PPARγ is the primary regulator of adipogenesis, while C/EBPα plays a role in maintaining PPARγ levels and promoting insulin sensitivity. The study also highlights the importance of PPARγ in the development of white adipose tissue and the need for other factors in brown adipose tissue.The study investigates the role of C/EBPα and PPARγ in adipogenesis, a process where precursor cells differentiate into fat cells. Both proteins are critical transcription factors, but their precise roles have been unclear due to their positive feedback loop regulation. The authors created an immortalized line of fibroblasts lacking PPARγ to test whether C/EBPα can promote adipogenesis independently of PPARγ. They found that C/EBPα alone is insufficient to induce adipogenesis in the absence of PPARγ, suggesting that these factors participate in a single pathway of fat cell development with PPARγ being the proximal effector. This finding supports the idea that PPARγ is the primary regulator of adipogenesis, while C/EBPα plays a role in maintaining PPARγ levels and promoting insulin sensitivity. The study also highlights the importance of PPARγ in the development of white adipose tissue and the need for other factors in brown adipose tissue.