Announce my AS through Cloudflare?

Hello,

I have checked the docs and consulted my favourite search engine (Yahoo of course) but could not find an answer to my question:
If I become a customer of cloudflare, will I be able to announce my proper BGP AS through them? Or will I be limited to use their IP space?

I am looking at using their CDN as a DDoS protection for my own AS.

Thanks.