SH2D1A（SH2 domain containing 1A），癌症关联基因，基因ID：4068，这个基因编码一种蛋白质，在双向刺激T和B细胞中起主要作用。这种蛋白质含有SH2结构域和短尾。它与信号淋巴细胞活化分子相结合，从而通过阻止含有shp-2信号转导分子的sh2结构域进入其对接位点而起到抑制这种跨膜蛋白的作用。这种蛋白质还可以与活化的t、b和nk细胞上表达的其他相关表面分子结合，从而改变这些细胞的信号转导途径。该基因突变导致淋巴增生综合征x连锁1型或duncan病，一种罕见的免疫缺陷，其特征是极易感染eb病毒，症状包括严重的单核细胞增多症和恶性淋巴瘤。已发现该基因编码不同亚型的多个转录变体。[由RefSeq提供，2008年7月]This gene encodes a protein that plays a major role in the bidirectional stimulation of T and B cells. This protein contains an SH2 domain and a short tail. It associates with the signaling lymphocyte-activation molecule， thereby acting as an inhibitor of this transmembrane protein by blocking the recruitment of the SH2-domain-containing signal-transduction molecule SHP-2 to its docking site. This protein can also bind to other related surface molecules that are expressed on activated T， B and NK cells， thereby modifying signal transduction pathways in these cells. Mutations in this gene cause lymphoproliferative syndro。