Dendritic cells (DCs) are one of the key populations controlling immune responses. To establish a cell depletion system in vivo, human diphtheria toxin (DT) receptor (DTR) is transduced to the mice in which DTR is expressed under the control of a specific promoter. In these mice, DTR-expressing cells are inducibly depleted after DT injection. Using this system, analysis of mouse models in which DTR was expressed under the CD11c promoter has contributed to our knowledge of DC biology by depleting CD11c(+) cells. Other mouse models to inducibly eliminate specific DC subsets upon DT treatment have been also generated. Here, we describe a new mouse model in which the XCR1(+) DC subset is inducibly and transiently depleted in vivo.