A 36-year-old man underwent a periodic medical examination for early colon cancer originating from classical FAP (adenomatous polyposis coli (APC) gene in 5q21 analysis, codon 1–1800: exon 15, codon 795, 1 bp deletion of C: CTC→CT) for which laparoscopic-assisted subtotal colectomy with a J-shaped ileal pouch-rectal anastomosis was performed 3 years earlier. The gene discussed is APC; the disease is colonic neoplasm.