RXRA and periodontitis: The present study aimed to evaluate the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), retinoid X receptor-α (RXR-α), and vitamin D receptor (VDR) in gingival tissues from periodontally healthy individuals and from patients with grade B and grade C periodontitis, with the primary comparison focusing on grade-related differences within the same disease stage (stage 3).