TNF and periodontitis: This study investigated the gingival crevicular fluid (GCF) levels of complement-C1q tumor necrosis factor related protein-1 (CTRP-1), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) following non-surgical periodontal therapy (NSPT) in systemically healthy individuals with periodontal health (H), generalized gingivitis (G), and stage III grade B periodontitis (P).