The LASP1 gene was initially identified from a cDNA library of metastatic axillary lymph nodes (MLN) from human breast cancer and therefore called MLN50. The gene was mapped to chromosomal region 17q11-q21.3, a region known to contain the c-erbB-2 (HER-2/neu) and the BRCA1 oncogene and to be altered in 20–30% of all breast cancers (Tomasetto et al, 1995a, 1995b). This evidence concerns the gene ERBB2 and breast cancer.