EPAC proteins may regulate lipid metabolism-related processes such as triglyceride synthesis, fatty acid uptake and intracellular transport, fatty acid synthesis and esterification, and the expression of lipid droplet-associated proteins by acting on downstream transcription factors such as PPARγ and SREBP1, thereby promoting lipid droplet expansion in breast cancer cells [94]. The gene discussed is RAPGEF4; the disease is breast carcinoma.