Evidence of CDK9 inhibition based on RNAP II P-Ser2 and MCL1 downregulation was apparent across all 7 xenograft tumor models (Figure S5) even though measuring RNAP II P-Ser2 at the 6 hr time point used for this study, focusing on apoptotic response, was slightly late for those early markers based on kinetic studies described above (Figure 5A). This evidence concerns the gene CDK9 and neoplasm.