Glypican-3 is an integral membrane protein that plays a crucial role in regulating tissue and organ growth, primarily through interactions with growth factors like insulin-like growth factor II (IGF-II) and fibroblast growth factor 2 (FGF-2). This regulation is vital for normal development, as dysregulation of glypican-3 can lead to conditions such as Simpson-Golabi-Behmel syndrome, which is characterized by significant pre- and post-natal overgrowth. Glypican-3 is anchored to the cell membrane via a glycosyl-phosphatidyl-inositol (GPI) anchor and is predominantly expressed in embryonic mesodermal tissues, including the lung, liver, and kidney. Understanding glypican-3 function is essential, as downregulation through mechanisms such as promoter hypermethylation or repression of specific transcription factors can have profound implications for growth regulation and developmental processes.