IFNA1 and chickenpox: Possibly, in APS1, there might be dysregulated surges in IFN secretion in vivo, e.g., in response to childhood infections such as Varicella; indeed, we also find modest neutralising titres against IFN-αs, IFN-ω, and IFN-λ1 (but not IFN-β or IFN-γ) in some hyperimmune anti-Varicella Ig preparations from healthy donors ([54]; A. Meager, unpublished data).