STING1 and neoplasm: Importantly, PRMT3 inhibitor treatment of Myc/Trp53-/- mice also led to a drastic increase of phosphorylation of TBK1, IRF3, and STING in the spontaneous HCC tumor samples, accompanied by a dramatic decrease in ADMA that confirmed the effectiveness of PRMT3 inhibition in vivo (Fig. 6G).