Ventricular myocytes were cultured in six well plates at 100,000 per well. Myocytes were treated with control or KMT5A siRNA as indicated for 48 hours and/or treated with phenylephrine (20 µmol/L) for 1 h before harvest. CUT&RUN was performed using the CUTANA™ CUT&RUN Kit (EpiCypher, 14-1048) and K-MetStat Panel (EpiCypher, 19-1002) according to the manufacturer's instructions with minor modification.55 Cells were immobilized on concanavalin A coated magnetic beads (EpiCypher catalog no. 21-1401) and incubated overnight (4 °C with gentle rocking) with 1 µg antibody per sample. CUTANA pAG-MNase was then added to samples to cleave DNA selectively at antibody-bound chromatin. 10 ng genomic DNA was used to prepare sequencing libraries with the KAPA HTP/LTP Library Preparation Kits (Roche catalog no. 07961880001). Libraries were sequenced with NovaSeq 6000 system according to the manufacturer's instructions. Paired-end fastq files were aligned to the rn7 reference genome using the Bowtie v.2 algorithm.