Wonderful news! I can't believe how fast things happen over there, it took me 12 months to get to the IUI stage, I'm so pleased for you that its all moving so much faster for you guys and how exciting!
I also started with natural IUI cycles to reduce the risk of multiples. I had 3 which didn't work but I know of people who have conceived with their first one. I'm now beginning stimulated cycles and I have to say the possibility of multiples really concerns me.
I'm not sure about the cillia thing. I know that many years ago (before recent research) people used to think that CF was caused by the cillia in the lungs not working properly, so not moving the mucus along, but this was discounted when they discovered more about it. So may be your RE has heard about this in the past?
I look forward to hearing about the upcoming IUI!