['BACKGROUND/ AIM: The present study was performed in order to investigate the distribution of transplanted bone marrow-derived cells (BMDCs) in normal and neoplastic tissues.', 'A microchimeric mouse model harboring traceable BMDCs was created by injecting labeled BMDCs into adenovirus-expressing Cre (AdenoCre)-infected, irradiated, LSL-K-ras(G12D) p53(fl/fl) mice.', 'In the normal mice, transplanted cells were detected in the femur, tibia, lung, heart, kidney and spleen of recipient mice. The transplanted BMDCs were detected predominantly in the connective tissue around the smaller bronchioles of normal lung parenchyma. In the lung tumor-bearing mice, the transplanted BMDCs were detected within the tumor tissue and more abundantly in the connective tissue adjacent to the tumor mass.'] Do bone marrow-derived cells participate in the formation of normal and neoplastic lung stroma?