I've e-mailed Malcomb about this in the past, but I can't remember if I got a response. TB would be a great target, since most cases are pulmonary, ideally suited for aerosol delivery, and the current treatment is not very effective, and it's developing many resistant strains. There are so many potential targets that I think they just don't have the staff to go after everything. Seems like something the Gates Foundation would be willing to support.