SMARCA4（SWI/SNF related， matrix associated， actin dependent regulator of chromatin， subfamily a， member 4），癌症关联基因，基因ID：6597，该基因编码的蛋白是Swi/SNF蛋白家族的一员，与果蝇的布拉马蛋白相似。这个家族的成员有螺旋酶和ATP酶活性，被认为通过改变这些基因周围的染色质结构来调节某些基因的转录。编码蛋白是大型ATP依赖染色质重塑复合物snf/swi的一部分，这是染色质抑制的基因转录激活所必需的。此外，该蛋白能结合BRCA1，并调节致瘤蛋白CD44的表达。该基因突变导致2型横纹肌样肿瘤易感综合征。已发现编码该基因不同亚型的多种转录变体。The protein encoded by this gene is a member of the SWI/SNF family of proteins and is similar to the brahma protein of Drosophila. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein is part of the large ATP-dependent chromatin remodeling complex SNF/SWI， which is required for transcriptional activation of genes normally repressed by chromatin. In addition， this protein can bind BRCA1， as well as regulate the expression of the tumorigenic protein CD44. Mutations in this g。