My research has focused on the use of the SCID-hu Thy/Liv mouse model for preclinical evaluation of antiviral compounds and immunomodulating agents. The Thy/Liv model is constructed by implantation of organs supportive of human multilineage hematopoiesis and T-cell development (e.g., fetal liver and thymus) into the immunodeficient C.B-17 scid/scid mouse. Since 2000, I have been the Principal Investigator for a sole-sourced contract from NIH/NIAID, Tissue-Based Small Animal Model for HIV Drug Discovery funded to carry out these drug evaluations. The model has also been shown to be receptive to the surgical implantation of a number of other hematopoietic and nonhematopoietic human organ systems, including lymph node, small and large intestine, lung, skin, pituitary, ovary, and placenta. Mice with such implanted organs represent potential models that could be used to discover and evaluate stem cell populations normally resident within each of these organs.