Additional Study Information: The purpose of this study is to monitor you for any delayed side effects that may possibly be related to the experimental gene-modified therapy product you received in the Kite-sponsored study for Axicabtagene ciloleucel (axi-cel). The main study does not involve treatment. In the re-treatment portion, you will be provided access to a second course of treatment with lymphodepleting chemotherapy and axi-cel. Axi-cel is manufactured using your own blood cells. If you meet the requirements for the retreatment part of this study, the study doctor will confirm if leftover product from your participation in the previous Kite-sponsored study can be used for your second dose.