This book is more to say about how important is IMMUNOHISTOHEMISTRY (IHC) in diagnosis and prognosis of oral lesions ;specially (cyst and odontogenic tumors ) in oral lesions. As we know IHC is one of the most advanced diagnostic aid and it is used technique for diagnosis and for treatment planning in recent time frame. In this book, we will be dealing with one of the most important endothelial marker, VEGF (Vascular endothelial growth factor) shown to play a vital role to access the growth potential and angiogenesis of cysts and tumors through autocrine and paracrine pathways.