 Silence Therapeutics PLC LON:SLN, NASDAQ:SLN said had received a further US2mln from commercial partner Mallinckrodt under a deal potentially worth up to US2bn in milestones and royalties. In 2019, Silence was paid an upfront US20mln for the exclusive worldwide licence to short interfering ribonucleic acids siRNAs against one target, C3, and the option to licence siRNAs against two additional targets. 