As we look so different, our genomic sequences vary enormously. The differences in our genome, genetic variations, have played very significant roles in medical research and have contributed to improvement of medical managements in the last 2–3 decades. Genetic variations include germline variations, somatic mutations, and diversities in receptor genes of rearranged immune cells, T cells and B cells. Germline variants are in some cases causative of genetic diseases, are associated with the risk of various diseases, and also affect drug efficacies or adverse events. Some somatic mutations are causative of tumor development. Recent DNA sequencing technologies allow us to perform single-cell analysis or detailed repertoire analysis of B and T cells. It is critically important to investigate temporal changes in immune environment in various anatomical regions in the next one to two decades. In this review article, we would like to introduce the roles of genetic variations in medical fields in the past, at present and in the future.

由于我们看起来如此不同，我们的基因组序列差异很大。我们基因组的差异、遗传变异在医学研究中发挥了非常重要的作用，并在过去的 2-3 年中为改善医学管理做出了贡献。遗传变异包括种系变异、体细胞突变以及重排免疫细胞、T 细胞和 B 细胞受体基因的多样性。在某些情况下，生殖系变异是遗传疾病的原因，与各种疾病的风险相关，还会影响药物疗效或不良事件。一些体细胞突变是肿瘤发展的原因。最近的 DNA 测序技术使我们能够对 B 细胞和 T 细胞进行单细胞分析或详细的库分析。研究未来一到二十年不同解剖区域免疫环境的时间变化至关重要。在这篇综述文章中，我们想介绍基因变异在过去、现在和未来在医学领域的作用。