First off, if you don't know what HeLa cells are, look them up. Second, while I just thought of this now, the idea is that HeLa cells mutated and created like weird human versions of Henrietta Lacks, with either too many chromosones, too little, too many cells or organs, etc. The SCP itself isn't too useful, because everything it does has already been discovered by modern science.
Is it a good idea? I'm still brainstorming so any other ideas would help me out a lot. Thanks!