CX-5461是rRNA合成抑制剂,选择性抑制Pol I驱动的rRNA转录,IC50为142nM,对Pol II无效。;CX-5461 is an inhibitor of rRNA synthesis, selectively inhibits Pol I-driven transcription of rRNA with IC50 of 142 nM, has no effect on Pol II, and possesses 250- to 300-fold selectivity for inhibition of rRNA transcription versus DNA replication and protein translation.