Inclusion Criteria:  Patients over the age of 15 years and 3 months, diagnosed with lymphoma at Nîmes University Hospital as from 1999 onwards and for whom diagnostic tumor material is available.  Exclusion Criteria:  Patients aged 18 or over who have expressed their desire not to take part in the study. Patients under the age of 18 whose legal representatives have expressed their desire for the child not to take part in the study. Patients under legal guardianship.