SOD1 and neoplasm: Moreover, it is known that levels of SODs inversely correlate with metastatic ability of tumour cells (Kwee et al, 1991), and that SOD suppresses metastasis of tumour cells in vivo (Safford et al, 1994; Yoshizaki et al, 1994) and inhibits their motility and invasiveness (Muramatsu et al, 1995).