Therefore, we decided to use a model antigen (CMV-pp65) to establish suitable technologies, work-flows, standard operating procedures (SOP) and quality assurance programs to qualify local operators in Hemophilia Treatment Centers (HTC) for all the critical steps which were to be implemented in the assessment of FVIII-specific transcriptome signatures in PBMCs after short-term in vitro re-stimulation during the HIPS multicenter clinical trial. The gene discussed is F8; the disease is hemophilia.