CD24 and periodontitis: Isoforms of CD24 expressed as 33–35 kDa and 30 kDa entities typically contain N-glycosylation patterns including α2,3-sialic acid groups as primary sites for recognition by the L1 transmembrane receptor [7] that is also expressed by the epithelial attachment to the tooth and that lining the lesion of periodontitis (unpublished data).