REL and lymphadenitis: In conclusion, we have identified a transcriptomic signature from PBMC of patients with C. burnetii-associated lymphoma that consists of the overexpression of several genes including MIR17HG, REL and SP100. Patients with C. burnetii lymphadenitis presented high level of BCL2 mRNA in blood, shared a similar transcriptomic signature with patients infected with C. burnetii and were diagnosed with lymphoma.