Increased expression, protein, and activity levels of CASP3 and CASP9 have been found in gingival samples from sites of periodontitis as compared to healthy sites [44,45,46,47], which is in accordance with our study, which demonstrated increased CASP3 and CASP9 levels at transcriptional and protein level in gingiva from periodontitis patients. This evidence concerns the gene CASP9 and periodontitis.