We also described a negative correlation between amniotic sphingomyelin and the concentration of total IgG in AF that could be associated with the regulatory activity of sphingomyelin on the CD-1d antigen presentation to T and NK cells [62]; the negative correlation between amniotic PTX3 expression and anti-CadV1 IgG titres should be further investigated. This evidence concerns the gene PTX3 and atrial fibrillation.