The search for cancer cure from natural products have been practiced for over a century. For the last 25 years, El-Asmer and co-workers were pursuing the search for potential therapeutic agent or new drug models from snake venoms. This work was presented for partial fulfillment of M.D. in Biochemistry. A cytolytic, non-antigenic, 8 kDa, glycoprotein (Fraction VIb) was isolated from crude Naja nigricollis nigricollis spitting cobra venom. This protein is stable at different pH values and different temperatures up to 100 C, lethal to mice, with LD50 1.83 mg/kg. Small doses induced cytolytic effect on hepatocellular carcinoma, colon cancer and breast cancer cells while larger doses caused hemolysis of red blood cells. Thus, this protein can be considered a target compound for further researches as it can be a potential bio-therapeutic agent for cancer treatment, or a model for new drug design."