I’m not sure if you mean in life or for the project, but to be honest the answer is the same: running out of funding! Nature sciences are often underfunded, even though the work is so important (I think!) I hope we manage to keep securing funding so that we can sequence the genome of everything and provide this really good ‘library’ of sequences. I also really hope that I can keep getting funding for myself so I can keep doing the things I care about and think are important. I think a lot of us working in this field would be happy to work for free, but everyone has bills to pay and a life to support, so that’s not usually something we can do.