DPP7 (dipeptidyl peptidase 7) is a serine-type peptidase that plays crucial roles in protein catabolism and cellular metabolism 1. Structurally, DPP7 contains a conserved catalytic triad (Ser162, Asp418, His443) within an α/β-hydrolase domain and features a unique helical specificity domain that differs significantly from other dipeptidyl peptidases 1. In cancer contexts, DPP7 functions as a critical metabolic regulator in tumor-associated macrophages (TAMs), where it enhances fatty acid β-oxidation by preventing CPT1A degradation through competitive binding with TRIM25, promoting immunosuppressive M2 polarization 2. DPP7 also suppresses disulfidptosis by physically interacting with and stabilizing GPX4, protecting colorectal cancer cells from glucose deprivation-induced cell death while facilitating immune evasion from NK cells 3. Clinically, elevated DPP7 expression correlates with poor prognosis in colorectal cancer patients and serves as an independent prognostic factor 43. DPP7 has emerged as a potential biomarker for early Parkinson's disease, being consistently upregulated in cerebrospinal fluid and urine of treatment-naïve patients 5. Additionally, DPP7 is found in periodontopathic bacteria and may serve as a biomarker for periodontal disease 6.