I think some AI safety advocates have been arguing for great controls around nucleotide synthesis (e.g., impose greater data collection requirements or advanced screening for harmful sequences). It's surprisingly easy to order synthesized genes delivered to your doorstop. All you need is a credit card and a nucleotide sequence file!

Developing a bioweapon is already within reach for experts with sufficient funds, time, and motivation. That's more or less what gain-of-function research already does! Fortunately the barrier to entry is high enough that you don't see like... Boko Haram doing this. Or a lone-wolf nutjob. LLMs could definitely lower that barrier to entry though.