Inclusion criteria

At registration (pre-transplant):

1. Follicular lymphoma or Lymphoplasmacytic lymphoma or
2. HLA-identical sibling transplant to be performed using the fludarabine-melphalan-alemtuzumab conditioning regimen Small Cell Lymphocytic Lymphoma/CLL and beyond 1st line therapy
3. Aged ≥18 years, and <70 years
4. Written informed consent

Exclusion criteria

1. Histological evidence of high-grade ProT4 Trial Summary & Flowchart v1.0 23.02.11 transformation
2. Pregnant or lactating women
3. Life expectancy of <8 weeks
4. Currently taking part in any other interventional clinical research study (involving any IMP, ATMP or cellular therapy)
5. Organ dysfunction: Creatinine >200μmol/l, />Bilirubin >50μmol/l, or AST/ALT > 3x ULN Post-transplant
6. Active acute GvHD
7. Prior grade II-IV GvHD
8. Relapse or progressive disease
9. Primary or secondary graft failure
10. Other cellular therapies
11. Requirement for ongoing immunosuppression