The immune system plays an important role in protecting the body against malignancy. During cancer immunoediting, the immune system can recognize and keep checking the tumor cells by down-expression of some self-molecules or by increasing expression of some novel molecules. However, the microenvironment created in the course of cancer development hampers the immune ability to recognize and destroy the transforming cells. Human Leukocyte Antigen G (HLA-G) is emerging as immune checkpoint molecule produced more by cancer cells to weaken the immune response against them. HLA-G is a non-classical HLA class I molecule which is normally expressed in immune privileged tissues as a soluble or membrane-bound protein. HLA-G locus is highly polymorphic in the non-coding 3′ untranslated region (UTR) and in the 5′ upstream regulatory region (5′ URR). HLA-G expression is controlled by polymorphisms located in these regions, and several association studies between these polymorphic sites and disease predisposition, response to therapy, and/or HLA-G protein expression have been reported. Various polymorphisms are demonstrated to modulate its expression and this is increasingly finding more significance in cancer biology. This review focuses on the relevance of the HLA-G gene and its polymorphisms in cancer development. We highlight population genetics of HLA-G as evidence to espouse the need and importance of exploring potential utility of HLA-G in cancer diagnosis, prognosis and immunotherapy in the currently understudied African population.

免疫系统在保护身体免受恶性肿瘤侵害方面发挥着重要作用。在癌症免疫编辑过程中，免疫系统可以通过降低一些自身分子的表达或增加一些新分子的表达来识别并不断检查肿瘤细胞。然而，在癌症发展过程中产生的微环境阻碍了识别和破坏转化细胞的免疫能力。人类白细胞抗原 G (HLA-G) 正在成为由癌细胞产生的更多免疫检查点分子，以削弱针对它们的免疫反应。HLA-G 是一种非经典的 HLA I 类分子，通常在免疫特权组织中作为可溶性或膜结合蛋白表达。HLA-G基因座在非编码 3' 非翻译区 (UTR) 和 5' 上游调节区 (5' URR) 中具有高度多态性。HLA-G 表达受位于这些区域的多态性控制，并且已经报道了这些多态性位点与疾病易感性、对治疗的反应和/或 HLA-G 蛋白表达之间的关联研究。各种多态性被证明可以调节其表达，这在癌症生物学中越来越重要。本综述侧重于HLA-G基因及其多态性在癌症发展中的相关性。我们强调HLA-G的群体遗传学作为支持探索 HLA-G 在癌症诊断、预后和免疫治疗中的潜在用途的必要性和重要性的证据，目前研究不足的非洲人群。