ASS1 and melanoma: Silencing of Beclin1 will enhance cell death, suggesting that autophagy represents a survival strategy in ASS (−) melanoma cells [72]; however, the protective effect of autophagy may be an initial adaptation mechanism to arginine deprivation, because prolonging the time of arginine deprivation will impair the function of mitochondrial respiration and induce cytotoxic autophagy, at least partly leading to the death of ASS1-deficient breast cancer cells [73].