RB1 and cancer: Hence, it has been postulated that the depletionof arginine by ADI treatment can serve as a potential treatment strategyto combat Rb.102 Indeed, ADI-based therapyhas also gained tremendous attention to treat a variety of other cancers.103−106 Altogether, increased arginine levels in serum of Rb patients indicatethat circulating arginine is required to cope with the continuouslyincreasing demand of Rb cells for their growth and proliferation owingto their lack of ASS1 activity and overexpression of ADI enzyme.