Our results suggest that transcriptional profiling has the potential to identify a gene expression pattern in breast cancer that may lead to clinically useful predictors of pCR to T/FAC neoadjuvant therapy.

CREB-binding protein (CREBBP) is important for the cell-autonomous regulation of hematopoiesis, including the stem cell compartment. In the present study, we show that CREBBP plays an equally pivotal role in microenvironment-mediated regulation of hematopoiesis. We found that the BM microenvironment of Crebbp ؉/؊ mice was unable to properly maintain the immature stem cell and progenitor cell pools. Instead, it stimulates myeloid differentiation, which progresses into a myeloproliferation phenotype. Alterations in the BM microenvironment resulting from haploinsufficiency of Crebbp included a marked decrease in trabecular bone that was predominantly caused by increased osteoclastogenesis. Although CFU-fibroblast (CFU-F) and total osteoblast numbers were decreased, the bone formation rate was similar to that found in wild-type mice. At the molecular level, we found that the known hematopoietic modulators matrix metallo-

Background: We consider both univariate-and multivariate-based feature selection for the problem of binary classifi cation with microarray data. The idea is to determine whether the more sophisticated multivariate approach leads to better misclassifi cation error rates because of the potential to consider jointly signifi cant subsets of genes (but without overfi tting the data).