Since its inception in 1993, the University of Massachusetts Cancer Center has sought to elucidate new insights into normal and cancer cell biology. Investigators based at U Mass are beginning to translate this knowledge into clinical correlative studies and therapeutic approaches through the CALGB. For example, Dr. Mary-Ellen Taplin has described specific androgen receptor gene mutations that may target more effective treatments for hormone independent prostate cancer. These initial studies constitute one of the funded Correlative Science Studies through the CALGB and comprises one of the CALGB Core Labs. Based on our experience and substantial base in hematopoietic cell biology, a major focus of the U Mass Cancer Center has been in transplantion biology. Efforts have centered on (1) determining factors that enhance engraftment, (2) the development of entirely new transplant models using minimal myeloablation, (3) cord blood transplantation, (4) NOD-SCID preclinical transplant models to detect minimal residual disease, and (5) gene therapy approaches such as MDR1 transfer into normal hematopoietic stem cells. Many principles of hematopoietic stem cell biology """"""""are now being applied to solid organ systems, with investigators at U Mass evaluating growth characteristics of both normal and neoplastic cells by defining the malignant stem cell"""""""" in solid tumor systems and defining autocrine and paracrine loop pathways of growth control. Stem cell """"""""studies in breast cancer, prostate cancer, and glioblastoma"""""""" are ongoing and may provide important clinical correlative studies as companion studies to CALGB treatment protocols. Our Group Activities and Scientific contributions have increased significantly in the past four years. U Mass investigators in CALGB have contributed substantially to activities in Transplant, Breast Cancer, Prostate Cancer, Surgery, and Gastrointestinal Cancer. Administrative contributions through the Audit committee and other ad hoc committees have been substantial. Major efforts have led to improvement in accrual to Group Studies and improvement in the quality of data submitted on CALGB clinical trials.