This is a Long-term Follow-up (LTFU) study in patients who received BEAM-101 in the parent study (Study BTX-AUT-001). Eligible patients who received BEAM-101 will be asked to participate in this LTFU study prior to completing Study BTX-AUT-001. Patients who enter into this study will be followed for 13 years (a total of 15 years after receiving BEAM-101).