CD44 and periodontitis: CD44 plays a significant role in anoikis induction (Bunek et al., 2010; Cieply et al., 2015); therefore, the observed degradation of CD44 on gingival keratinocytes by gingipains could be one of the inducers of anoikis leading to a damage of the gingival epithelium during progression of periodontitis.