ASS1 and neuroblastoma: For this purpose, we performed capillary electrophoresis and time-of-flight mass spectrometry [36] using two neuroblastoma cell lines with or without CBR-5884 and arginine deiminase and compared the treatment effect on IMR-32 (high PHGDH expression, normal ASS1) and SK-N-SH (low PHGDH expression, deficient ASS1) cells.