- City of Hope (COH) pathology review confirms that research participant's diagnostic material is consistent with history of ALL with history of recurrence/progression/minimal residual disease (MRD) following prior therapy; additionally, CD19 positivity must be documented in a pathology report; however, it is not a requirement that the CD19 testing be performed by a COH pathologist; patients in second complete remission (CR2) or higher with history of CD19+ ALL on previous bone marrow biopsy are also eligible for the study