Isolated antigen binding molecules that specifically bind to an anti-CD19 scFv comprising SEQ ID NO: 1 are provided. The antigen binding molecules can be used in the methods provided herein.本發明提供經單離之抗原結合分子,其特異性結合包含SEQ ID NO: 1之抗CD19 scFv。該抗原結合分子可用於本發明所提供之方法。