Toyocamycin (Vengicide) is an adenosine analog produced by Streptomyces diastatochromogenes , acts as an XBP1 inhibitor. Toyocamycin blocks RNA synthesis and ribosome function, and induces apoptosis . Toyocamycin affects IRE1α-XBP1 pathway, and inhibits XBP1 mRNA cleavage with an IC 50 value of 80 nM with affecting IRE1α auto-phosphorylation. Toyocamycin specifically inhibits CDK9 with an IC 50 value of 79 nM.