The US National Science Foundation (NSF) and UK Research and Innovation (UKRI) have signed a Memorandum of Understanding (MOU) on Research Cooperation. The MOU provides an overarching framework to encourage collaboration between US and UK research communities and sets out the principles by which jointly supported activities might be developed. The MOU provides for a lead agency arrangement whereby proposals may be submitted to either NSF (via Research.gov or Grants.gov) or UKRI (via Je-S). The NSF Directorate for Biological Sciences (NSF/BIO) and the UKRI Biotechnology and Biological Sciences Research Council (BBSRC) are pleased to announce new topical areas associated with the lead agency opportunity. The lead agency opportunity allows for reciprocal acceptance of merit review through unsolicited mechanisms. Its goal is to help reduce some of the current barriers to working internationally. Proposals relevant to the following priority areas and agency programs are eligible to apply for the lead agency opportunity in 2020/2021: Biological Informatics, Microbes and the Host Immune System, and Quantum Biology and Synthetic Cell.