In a meta-analysis that included 4,625 patients with FAP [15], risk factors for development of a desmoid tumor included a family history (odds ratio [OR] 7.02, 95% confidence interval [CI] 4.15–11.9), GPVs in the APC gene located distal to codon 1399 (OR 4.37, 95% CI 2.14–8.91), a history of abdominal surgery (OR 3.35, 95% CI 1.33–8.41), and female sex (OR 1.57, 95% CI 1.13–2.18), with 41% of desmoid tumors occurring intra-abdominally. This evidence concerns the gene APC and desmoid tumor.