Inclusion Criteria (Arm A)
\* Disease Status - B cell precursor acute lymphoblastic leukemia (ALL) or B cell lymphoma
Who either:
* Experienced refractory or relapsed disease, treated with standard chemotherapy, without immunotherapy treatment.
OR
* Previously undergone standard of care immunotherapy with FDA approved therapies, such as Kymriah™ (CTL019, tisagenlecleucel), blinatumomab or
* Age: Greater than or equal to 0 year of age and less than or equal to 26 years of age.
Inclusion Criteria (Arm B)
* Disease Status - B cell precursor acute lymphoblastic leukemia (ALL) or B cell lymphoma
* Age: Greater than or equal to 0 year of age and less than or equal to 26 years of age
* Patients who are either:
* Undergoing evaluation for leukapheresis for planned standard of care tisagenlecleucel therapy, or planned for therapy with blinatumomab or inotuzumab. (Patients who received prior tisagenlecleucel, blinatumomab or inotuzumab on an established clinical trial and are now scheduled for commercial CAR, blinatumomab or inotuzumab therapy are also eligible) Or
* Experienced refractory or relapsed B cell precursor acute lymphoblastic leukemia (ALL) or B cell lymphoma
* Ability to give informed consent. All subjects ≥ 18 years of age must be able to give informed consent or have legal authorized representative (LAR) (i.e. parent or guardian) to consent, if not in capacity to give consent independently. For subjects \<18 years old their LAR must give informed consent. Pediatric subjects will be included in age appropriate discussion and written assent will be obtained for those \> 7 years of age, when appropriate, according to institutional procedures.