This protocol is designed as a long-term follow-up study of participants who will receive CAR-T cells as part of a clinical trial at the Medical College of Wisconsin/ Froedtert Hospital. The clinical trials include the following: Phase 1 Study of CAR-20/19-T Cells in Patients with Relapsed Refractory B Cell Malignancies (NCT03019055); Phase I Trial of BCMA-TGF-BETA CAR-T Cells in Relapsed, Refractory Myeloma (NCT05976555); CAR20.19.22 T-cells in Relapsed, Refractory B-cell Malignancies (NCT05094206); LV20.19 CAR T-Cells in Combination With Pirtobrutinib for Relapsed, Refractory B-cell Malignancies (NCT05990465); CAR-20/19-T Cells in Patients With Relapsed Refractory B Cell Malignancies (NCT04186520)