ＦＨＩＴ 基因定位于染色体３ｐ１４ ．２ 区域。因含有脆性位点ＦＲＡ３Ｂ，该基因具有不稳定性，且外显子在正常人群中存在一定的多态性。ＦＨＩＴ 基因在多种肿瘤中均有改变，以缺失为主，包括外显子和／ 或内含子的缺失，还可有外源序列的插入。目前认为ＦＨＩＴ 基因很可能是一个抑癌基因，与直接与外界接触的器官上皮肿瘤的发生有关。其抑癌机制可能以ＦＨＩＴ 蛋白与其相互作用蛋白的结合为主，而以水解酶活性作用次之。 The FHIT gene is located on chromosome 3p14. 2 areas. Because of the fragile site FRA3B, the gene is unstable and there is a certain polymorphism in the exon in the normal population. The FHIT gene is altered in many types of tumors and is mainly deletions, including the deletion of exons and/or introns, and the insertion of exogenous sequences. At present, it is considered that the FHIT gene is likely to be a tumor suppressor gene, which is related to the occurrence of epithelial tumors of the organs directly in contact with the outside world. Its anti-cancer mechanism may be based on the binding of FHIT protein and its interacting protein, while the role of hydrolytic enzyme activity is secondary.