Thus, even if it remains controversial, we do not think that a systematic assay of anti-IgA Abs is of great interest in PID patients, as its absence is not predictive of the absence of HS risk, and its presence is not a contraindication to the use of IgPs (regardless of whether they contain low or high levels of IgA). The gene discussed is CD79A; the disease is histiocytic sarcoma.