POLR2B（RNA polymerase II subunit B），癌症关联基因，基因ID：5431，该基因编码rna聚合酶ii（pol ii）的第二大亚单位，pol ii是一种依赖于dna的rna聚合酶，催化dna转录为mrna、snrna和microrna的前体。这个亚单位和最大的亚单位形成了polⅡ中央裂的对侧。该亚单位的瓣环区缺失导致转录延长率降低。选择性剪接导致多个转录变体[由RefSeq提供，2014年12月]This gene encodes the second largest subunit of RNA polymerase II (Pol II)， a DNA-dependent RNA polymerase that catalyzes the transcription of DNA into precursors of mRNA， snRNA and microRNA. This subunit and the largest subunit form opposite sides of the center cleft of Pol II. Deletion of the flap loop region of this subunit results in a decrease in the rate of transcriptional elongation. Alternative splicing results in multiple transcript variants. [provided by RefSeq， Dec 2014]。