Both H3K27ac and RNAPII-Ser2,5p FFPE-CUTAC on RELA- and PDGFB-driven brain tumors showed much better sensitivity based on number of peaks called and much higher FRiP values than either H3K27ac CUT&Tag on frozen kidney or FACT-seq on FFPEs (Fig. 3e, f). The gene discussed is RELA; the disease is brain neoplasm.