BCAS2 (breast carcinoma amplified sequence 2), also designated DAM1 (DNA amplified in mammary carcinoma 1 protein) or spliceosome-associated SPF 27, is a ubiquitously expressed nuclear protein that was originally identified as being overexpressed in various breast cancer cell lines. BCAS2 is now known to be a component of the spliceosome, participating in the removal of introns from mRNA precursors. BCAS2 specifically interacts (in a ligandindependent manner) with TR(beta) (thyroid hormone receptor (beta)), ER(alpha) (estrogen receptor (alpha)), ER(beta), PR (progesterone receptor), and PPAR(gamma) (Peroxisome proliferator-activated receptor (gamma)). BCAS2 functions as an ER coactivator and is capable of enhancing ER-mediated transcription. This suggests that BCAS2 is involved in the development of breast cancer.