MTA1 and breast cancer: The metastasis-associated gene 1 (mta1) was identified by differential cDNA screening using cell lines derived from highly metastatic mammary adenocarcinomas (Toh et al, 1994), and expression of metastasis-associated protein 1 (MTA1) correlated with the invasive and metastatic potential of cultured mammary tumour cells (Toh et al, 1994, 1995).