They found that amygdalin down‐regulated the cell cycle‐related genes: ATP‐binding cassette, exonuclease 1 (EXO1), sub‐family F and topoisomerase (DNA) I (TOP1) in SNU‐C4human colon cancer cells, thereby affecting tumor cell cycle, inhibiting cell proliferation and exerting its antitumor effect. This evidence concerns the gene TOP1 and neoplasm.