HEXIM1 and neoplasm: Another preclinical study reported that MYC and HEXIM1 act most robustly as tumour-based pharmacodynamic biomarkers for BETi and that the corresponding mRNAs did not show optimal correlation with drug accumulation within blood samples.111 Thus, MYC modulation (repression) in particular might hold more promise as an indicator of drug activity than its amplification does in predicting drug response.