The CDK9 protein plays a central role in transcriptional regulation, promoting the transition from ineffective to efficient elongation by phosphorylating POLR2A, SUPT5H, and RDBP. As part of the CDK9/cyclin-T complex, it participates in phosphorylation events affecting EP300, MYOD1, RPB1/POLR2A, AR, DSIF, and NELFE. CDK9-CCNT2 Heterodimer Protein, Human (sf9, GST, Flag, His) is the recombinant human-derived CDK9-CCNT2, expressed by Sf9 insect cells, with N-His, N-GST, N-Flag labeled tag.