CDK7/9-IN-1 is a cyclin-dependent kinases 7/9 ( CDK7/9 ) inhibitor. CDK7/9-IN-1 selectively inhibits CDK7 over CDK9. CDK7/9-IN-1 inhibits CDK7 with IC 50 s of 0.0656 μM and 0.00574 μM without pre-incubation and after 3 hours pre-incubation, respectively. CDK7/9-IN-1 inhibits CDK9 with an IC 50 of 2.14 μM after 3 hours pre-incubation. CDK7/9-IN-1 can be used for the research of cancer.