The present disclosure is directed to novel CD133 binding agents. The present disclosure also provides for detecting CD133 expressing cells and / or quantifying the CD133 expression level of the cells, for targeting CD133 expressing cells, for reducing CD133 levels in CD133 expressing cells, and The present invention is directed to the use of a novel CD133 binding agent for treating or preventing cancer. [Selection] Figure 2本開示は新規CD133結合剤を対象とする。本開示はまた、CD133発現細胞を検出し、かつ/または細胞のCD133発現レベルを定量化するための、CD133発現細胞をターゲッティングするための、CD133発現細胞中のCD133レベルを低下させるための、および癌を治療または予防するための、新規CD133結合剤の使用を対象とする。【選択図】図2