Carbon nanotube (CNT) monolayer patterns are utilized to control the growth of mesenchymal stem cells (MSCs) (see figure). MSCs exhibit preferential growth on CNT patterns, suggesting that the CNT monolayer does not have a harmful effect on the MSCs. Furthermore, the growth of MSCs on swCNT patterns between electrodes is demonstrated. These results show that CNT patterns have enormous potential as a new platform for basic research and applications using stem cells.