The first enzyme studied under artificial cell encapsulation was asparaginase for the treatment of lymphosarcoma in mice. This treatment delayed the onset and growth of the tumor. These initial findings led to further research in the use of artificial cells for enzyme delivery in tyrosine dependent melanomas. These tumors have a higher dependency on tyrosine than normal cells for growth, and research has shown that lowering systemic levels of tyrosine in mice can inhibit growth of melanomas. The use of artificial cells in the delivery of tyrosinase; and enzyme that digests tyrosine, allows for better enzyme stability and is shown effective in the removal of tyrosine without the severe side-effects associated with tyrosine depravation in the diet.